Mostly Unpublished Game Boy Cheats ;)

red    marked cheats are unique, not listed on any site (tell me if not).
brown marked cheats from various other sources like gamefaqs.com etc, checked and fixed if necessary.
gray   marked disabled or missed cheats buried inside game ROM.

  3 Choume no Tama - Tama and Friends - 3 Choume Obake Panic!!
  4-in-1 Fun Pak
  A-mazing Tater (USA), Puzzle Boy II (Japan)
  Adventure Island (USA), Takahashi Meijin no Bouken-jima II (Japan)
  Adventure Island II - Aliens in Paradise (USA), Takahashi Meijin no Bouken-jima III (Japan)
  Adventures of Lolo (USA), Lolo no Daibouken (Japan)
  Adventures of Rocky and Bullwinkle, The
  Aerostar (USA), Aero Star (Japan)
  After Burst
  Akazukin Chacha
  Aladdin
  Alien vs Predator - The Last of His Clan (USA), Alien vs Predator (Japan)
  All-Star Baseball 1999
  Amazing Penguin (USA, Europe), Osawagase! Penguin Boy (Japan)
  Amazing Spider-Man, The
  America Oudan Ultra Quiz
  America Oudan Ultra Quiz Part 2
  America Oudan Ultra Quiz Part 3 - Champion Taikai
  America Oudan Ultra Quiz Part 4
  Amida
  Animal Breeder
  Animal Breeder 2
  Animaniacs
  Another Bible
  Aoki Densetsu Shoot!
  Arcade Classic - Battle Zone & Super Breakout, Super Breakout (Single game cart)
  Arcade Classic No. 1 - Asteroids, Asteroids (Single game cart)
  Arcade Classic No. 3 - Galaga, Namco Gallery Vol.1 - Galaga
  Arcade Classic No. 4 - Defender
  Arcade Classic No. 4 - Joust
  Aretha II
  Aretha III
  Asmik-kun World 2
  Asterix
  Asterix & Obelix
  Atomic Punk (USA), Bomber Boy (Japan), Dynablaster (Europe)
  Attack of the Killer Tomatoes
  Avenging Spirit (USA, Europe), Phantasm (Japan)
  Bakenou TV '94
  Bakenou V3
  Bakuchou Retrieve Master
  Bakuchou Retsuden Shou - Hyper Fishing
  Banishing Racer
  Batman
  Batman - Return of the Joker
  Batman - The Animated Series
  Batman Forever
  Battle Arena Toshinden (USA, Europe), Nettou Toshinden (Japan)
  Battle Bull
  Battle City
  Battle Crusher
  Battle Pingpong
  Battle Unit Zeoth, Jet Pack (Prototype)
  Battle of Kingdom
  Battle of Olympus, The
  Beavis and Butt-head
  Beethoven
  Beetlejuice
  Best of the Best - Championship Karate (USA), Kick Boxing, The (Japan)
  Bikkuri Nekketsu Shin Kiroku! - Dokodemo Kin Medal
  Bill & Ted's Excellent Game Boy Adventure
  Bionic Commando
  Bishoujo Senshi Sailor Moon
  Black Bass - Lure Fishing (USA), Hyper Black Bass (Japan), Hyper Black Bass '95 Black Label (Japan Rerelease)
  Blades of Steel (USA, Europe), Konamic Ice Hockey (Japan)
  Blaster Master Boy (USA), Blaster Master Jr. (Europe), Bomber King - Scenario 2 (Japan)
  Block Kuzushi GB
  Blues Brothers, The Jukebox Adventure
  Bomb Jack
  Bomberman GB (USA), Bomberman GB 2 (Japan)
  Bomberman GB 3
  Bonk's Adventure (USA), B.C. Kid (Europe), GB Genjin (Japan)
  Bonk's Revenge (USA), B.C. Kid 2 (Europe), GB Genjin 2 (Japan)
  Booby Boys
  Boomer's Adventure in ASMIK World (USA), Teke Teke! Asmik-kun World (Japan)
  Boxxle (USA), Soukoban (Japan)
  Boxxle II (USA), Soukoban 2 (Japan)
  Bram Stoker's Dracula
  BreakThru!
  Bubble Bobble
  Bubble Bobble Part 2 (USA), Bubble Bobble Jr. (Japan)
  Bubsy II
  Burai Fighter Deluxe
  Bust-A-Move 2 - Arcade Edition (USA), Puzzle Bobble GB (Japan)
  Bust-A-Move 3 DX
  Cadillac II
  Captain Tsubasa J - Zenkoku Seiha e no Chousen
  Captain Tsubasa VS
  Card Game
  Castelian (USA, Europe), Kyoro-chan Land (Japan)
  Castle Quest
  Castlevania II - Belmont's Revenge (USA), Dracula Densetsu II (Japan)
  Castlevania Legends (USA), Akumajou Dracula - Shikkoku Taru Zensoukyoku - Dark Night Prelude (Japan)
  Catrap (USA), Pitman (Japan)
  Cave Noire
  Chachamaru Boukenki 3 - Abyss no Tou
  Chachamaru Panic
  Chalvo 55 - Super Puzzle Action
  Championship Pool
  Chessmaster, The (USA, Japan), New Chessmaster, The (USA, Europe, Japan Rereleases)
  Chibi Maruko-chan 2 - Deluxe Maruko World
  Chibi Maruko-chan 3 - Mezase! Game Taishou no Maki
  Chiki Chiki Machine Mou Race
  Chikyuu Kaihou Gun ZAS
  Choplifter III
  Chou Mashin Eiyuu Den Wataru: Mazekko Monster 2
  Chousoku Spinner (Yo for It)
  Chuck Rock
  Cliffhanger
  Collection Pocket
  College Slam
  Contra (Japan), Operation C (USA), Probotector (Europe)
  Contra - The Alien Wars (USA), Contra Spirits (Japan), Probotector 2 (Europe)
  Cool Spot
  Cool World
  Cosmo Tank
  Crayon Shin-chan - Ora to Shiro wa Otomodachi Da yo
  Crayon Shin-chan 2 - Ora to Wanpaku Gokko Dazo
  Crayon Shin-chan 3 - Ora no Gokigen Athletic
  Crayon Shin-chan 4 - Ora no Itazura Daihenshin, Super Mario 4 (Pirate)
  Crystal Quest
  Cutthroat Island
  Cyraid (USA), Bakuretsu Senshi Warrior (Japan)
  DX Bakenou Z
  Daedalian Opus (USA), Bouken! Puzzle Road (Japan)
  Daffy Duck - The Marvin Missions
  Daiku no Gen-san - Robot Teikoku no Yabou
  Darkwing Duck
  Days of Thunder
  Dead Heat Scramble
  Dennis the Menace (USA), Dennis (Europe)
  Desert Strike - Return to the Gulf
  Dexterity (USA), Funny Field (Japan)
  Dick Tracy
  Dino Breeder, Jurassic Park 3 (Pirate)
  Dino Breeder 2
  Disney's Mulan
  Dodge Boy
  Donkey Kong
  Donkey Kong Land (USA), Super Donkey Kong GB (Japan)
  Donkey Kong Land 2 (USA), Donkey Kong Land (Japan)
  Donkey Kong Land III
  Doraemon - Taiketsu Himitsu Dougu!!
  Doraemon 2 - Animal Planet Densetsu
  Doraemon Kart
  Doraemon no Study Boy 5 - Shou 2 Sansuu Keisan
  Double Dragon
  Double Dragon II (USA), Nekketsu Kouha Kunio-kun - Bangai Rantou Hen (Japan)
  Double Yakuman
  Double Yakuman II
  Double Yakuman Jr.
  Downtown Special - Kunio-kun no Jidaigeki dayo Zenin Shuugou!
  Dragon Ball Z - Gokuu Gekitouden
  Dragon Slayer - Nemuri no Oukan
  Dragon Slayer I
  Dropzone
  Duck Tales 2
  Dungeon Land
  F-1 Race
  FIFA - The Road to the World Cup '98 (USA), World Cup '98 (Europe)
  FIFA International Soccer
  FIFA Soccer '96
  FIFA Soccer '97
  Faceball 2000
  Family Jockey 2 - Meiba no Kettou
  Famista 2
  Famista 3
  Felix the Cat
  Ferrari Grand Prix Challenge
  Fidgetts, The
  Final Fantasy Legend II (USA), Sa-Ga 2 - Hihou Densetsu (Japan)
  Final Fantasy Legend, The (USA), Makai Toushi Sa-Ga (Japan)
  Fire Dragon (Unlicensed)
  Fire Fighter
  Fish Dude (USA), Uoozu (Japan)
  Fist of the North Star (USA), Hokuto no Ken - Seizetsu Juuban Shoubu (Japan)
  Flash, The
  Fleet Commander VS
  Flintstones, The
  Flintstones, The - King Rock Treasure Island
  Football International (USA, Europe), Soccer (Japan)
  Fortified Zone (USA), Ikari no Yousai (Japan)
  Frank Thomas Big Hurt Baseball
  Frisky Tom
  From TV Animation Slam Dunk - Gakeppuchi no Kesshou League
  From TV Animation Slam Dunk 2 - Zenkoku e no Tip Off
  Fushigi no Dungeon - Fuurai no Shiren GB - Tsukikage Mura no Kaibutsu
  Game & Watch Gallery (USA, Europe), Game Boy Gallery (Japan), Game Boy Gallery 2 (Australia)
  Game & Watch Gallery 2 (USA), Game Boy Gallery 2 (Japan), Game Boy Gallery 3 (Australia)
  Game Boy Gallery (USA)
  Game Boy Wars (Japan), Game Boy Wars Turbo (Japan, Rerelease), Game Boy Wars Turbo - Famitsu Version (Japan, Rerelease)
  Game de Hakken!! Tamagotchi 2
  Game Genie V1.17 BIOS (Unlicensed)
  Game of Harmony, The
  Ganbare Goemon - Sarawareta Ebisumaru
  Ganso!! Yancha Maru
  Garms - Operation Gundam
  GB Genjin Land - Viva! Chikkun Oukoku
  GB Pachi-Slot Hisshouhou! Jr.
  GBKiss Mini Games
  Gear Works
  Gekitou Power Modeller
  Gem Gem
  Genki Bakuhatsu Gambaruga
  Ghostbusters II
  GI King! - Sanbiki no Yosouya
  Ginga - Card & Puzzle Collection (Tornado Appetizer)
  Go Go Ackman
  Go! Go! Hitchhike
  Go! Go! Tank
  Goal! (USA, Europe), Jaleco J.Cup Soccer (Eerly Japan), Takeda Nobuhiro no Ace Striker (Japan, Rerelease)
  Godzilla (USA), Godzilla-kun - Kaijuu Daikessen (Japan)
  Golf
  Goukaku Boy GOLD - Shikakui Atama o Maruku Suru - Kanji no Tatsujin
  Goukaku Boy GOLD - Shikakui Atama o Maruku Suru - Keisan no Tatsujin
  Goukaku Boy Series - 99 Nendo Ban Eitango Center 1500
  Goukaku Boy Series - Eijukugo Target 1000
  Goukaku Boy Series - Eiken 2kyuu Level no Kaiwa Hyougen 333
  Goukaku Boy Series - Eitango Target 1900
  Goukaku Boy Series - Gakken - Kanyouku Kotowaza 210
  Goukaku Boy Series - Gakken - Rekishi 512
  Goukaku Boy Series - Gakken - Yojijukugo 288
  Goukaku Boy Series - Kirihara Shoten Hinshutsu Eibunpou Gohou Mondai 1000
  Goukaku Boy Series - Koukou Nyuushi Derujun - Chuugaku Eijukugo 350
  Goukaku Boy Series - Koukou Nyuushi Derujun - Chuugaku Eitango 1700
  Goukaku Boy Series - Koukou Nyuushi Derujun - Kanji Mondai no Seifuku
  Goukaku Boy Series - Koukou Nyuushi Derujun - Rekishi Nendai Anki Point 240
  Goukaku Boy Series - Koukou Nyuushi Derujun - Rika Anki Point 250
  Goukaku Boy Series - Nihonshi Target 201
  Goukaku Boy Series - Shikakui Atama o Maruku Suru - Kokugo Battle Hen
  Goukaku Boy Series - Shikakui Atama o Maruku Suru - Rika Battle Hen
  Goukaku Boy Series - Shikakui Atama o Maruku Suru - Sansuu Battle Hen
  Goukaku Boy Series - Shikakui Atama o Maruku Suru - Shakai Battle Hen
  Goukaku Boy Series - Shikakui Atama o Maruku Suru - Suuji de Asobou Sansuu Hen
  Goukaku Boy Series - Yamakawa Ichimonittou - Nihonshi B Yougo Mondaishuu
  Goukaku Boy Series - Yamakawa Ichimonittou - Sekaishi B Yougo Mondaishuu
  Goukaku Boy Series - Z Kai - Kyukyoku no Kobun Tango
  Gradius - The Interstellar Assault (USA), Nemesis II - The Return of the Hero (Europe), Nemesis II (Japan)
  Grander Musashi RV
  Great Greed (USA), Vitamina Oukoku Monogatari (Japan)
  HAL Wrestling (USA), Pro Wrestling (Japan)
  Hammerin' Harry - Ghost Building Company (USA), Daiku no Gen-san - Ghost Building Company (Japan)
  Harvest Moon GB (USA), Bokujou Monogatari GB (Japan)
  Hayaoshi Quiz - Ouza Ketteisen (The King of Quiz)
  Heavyweight Championship Boxing (USA), Boxing (Japan)
  Heisei Tensai Bakabon
  Hercules
  Hero Shuugou!! Pinball Party
  Hiden Inyou Kikouhou - Ca Da
  Higashio Osamu Kanshuu Pro Yakyuu Stadium '92
  High Stakes Gambling
  Hit the Ice - VHL - The Official Video Hockey League
  Hoi Hoi - Game Boy Ban (Japan), Stop That Roach! (USA)
  Holy Bible, The - King James Version (Wisdom Tree, Unlicensed)
  Home Alone 2 - Lost In New York
  Hon Shougi
  Hong Kong
  Hook
  Hudson Hawk
  Hugo 2
  Humans, The
  Hunchback of Notre Dame, The - Topsy Turvy Games
  Hunt for Red October, The
  Hyper Lode Runner
  Ikari no Yousai 2
  Incredible Crash Dummies, The
  Initial D Gaiden
  Iron Man X-O Manowar in Heavy Metal
  Ishidou - The Way of Stones
  Itchy & Scratchy - Miniature Golf Madness
  Itsudemo! Nyan to Wonderful
  J.League Fighting Soccer - The King of Ace Strikers
  Jack Nicklaus Golf
  James Bond 007
  Jankenman
  Jelly Boy
  Jetsons, The - Robot Panic
  Jikuu Senki Mu
  Jinsei Game
  Joe & Mac (USA), Joe & Mac - Caveman Ninja (Europe)
  Joshua (Wisdom Tree, Unlicensed)
  Judge Dredd
  Jurassic Park
  Jurassic Park 2 - The Chaos Continues
  Kachiuma Yosou Keiba Kizoku (Japan), Kachiuma Yosou Keiba Kizoku Ex'94 (Japan, Rerelease), Kachiuma Yosou Keiba Kizoku Ex'95 (Japan, Rerelease)
  Kaeru no Tame ni Kane wa Naru
  Kaguya Hime Pachinko
  Kaijuu Ou Godzilla
  Kamen Rider SD - Hashire! Mighty Riders
  Kandume Monsters
  Karakuri Kengou Den Musashi Lord
  Karamuchou no Daijiken
  Kaseki Sousei Reborn
  Kattobi Road
  Kenyuu Densetsu Yaiba
  Kid Dracula (USA), Akumajou Special - Boku Dracula-kun (Japan)
  Kid Icarus - Of Myths and Monsters
  Kidou Keisatsu Patlabor (Mobile Police Patlabor) in Nerawareta Machi 1990
  Kikou Keisatsu Metal Jack
  Killer Instinct
  King of Fighters '95, The (USA), Nettou The King of Fighters '95 (Japan)
  King of Fighters, The - Heat of Battle (Europe), Nettou The King of Fighters '96 (Japan), Nettou The King of Fighters '97 (Pirate), King of Fighters '98, The (Pirate)
  Kingyo Chuuihou! - Wapiko no Wakuwaku Stamp Rally!
  Kinin Koumaroku Oni
  Kirby's Block Ball (USA), Kirby no Block Ball (Japan)
  Kirby's Dream Land (USA), Hoshi no Kirby (Japan)
  Kirby's Pinball Land (USA), Kirby no Pinball (Japan)
  Kirby's Star Stacker (USA), Kirby no Kirakira Kids (Japan)
  Kitchen Panic
  Kiteretsu Daihyakka - Bouken Ooedo Juraki
  Kizuchi da Quiz da Gen-san da!
  Klax (Japan, Hudson Soft)
  Koi Wa Kakehiki
  Koro Dice
  Kung-Fu Master (USA), Spartan X (Japan)
  Kuusou Kagaku Sekai Gulliver Boy - Kuusou Kagaku Puzzle Purittopon!!
  Kwirk (USA, Europe), Puzzle Boy (Japan)
  Lamborghini American Challenge
  Lawnmower Man, The (Europe), Virtual Wars (Japan)
  Legend of Zelda, The - Link's Awakening (USA, Europe), Zelda no Densetsu - Yume o Miru Shima (Japan)
  Legend of the River King GB (USA, Europe), Kawa no Nushi Tsuri 3 (Japan)
  Lemmings
  Lemmings 2 - The Tribes
  Les Aventures De TinTin - Le Temple du Soleil (Tintin - Prisoners of the Sun)
  Lethal Weapon
  Lion King, The
  Little Indian (An Indian in the City, Un Indien Dans La Ville)
  Little Master 2 - Raikou no Kishi
  Little Mermaid, The
  Lock 'N Chase
  Looney Tunes (USA), Looney Tunes - Bugs Bunny to Yukai na Nakama-tachi (Japan)
  Lost World, The - Jurassic Park (USA), Monde Perdu, Le - Jurassic Park (France)
  Lucky Luke
  Lucle
  Mach Go Go Go
  Madden '95
  Madden '96
  Magic Ball (Unlicensed)
  Magical Taruruuto-kun
  Magical Taruruuto-kun 2 - Raibaa Zone Panic!!
  Magnetic Soccer
  Mahou Kishi Rayearth (Magical Knight Rayearth)
  Mahou Kishi Rayearth (Magical Knight Rayearth) 2nd - The Missing Colors
  Makaimura Gaiden - The Demon Darkness
  Mario's Picross (USA, Europe), Mario no Picross (Japan)
  Marmalade Boy
  Masakari Densetsu - Kintarou Action Hen
  Masakari Densetsu - Kintarou RPG Hen
  Maus, Die
  Max (USA, Europe), Rubble Saver II (Japan)
  Medarot (Kabuto, Kuwagata, Parts Collection 1 and 2 versions)
  MegaMemory v1.0 by Interact
  Megaman IV (USA), Rockman World 4 (Japan)
  Megaman V (USA), Rockman World 5 (Japan)
  Megami Tensei Gaiden - Last Bible
  Megami Tensei Gaiden - Last Bible II
  Meitantei Conan - Chika Yuuenchi Satsujin Jiken
  Meitantei Conan - Giwaku no Gouka Ressha
  Meng Huan Zhi Xing (Phantasy Star) (Unlicensed)
  Mercenary Force (USA, Europe), Tenjin Kaisen (Japan)
  Metal Masters
  Metroid II - Return of Samus
  Mick & Mack as the Global Gladiators (Prototype)
  Mickey no Tokyo Disneyland - Cinderella-jou Mystery Tour
  Mickey's Chase
  Micro Machines
  Midori no Makibaou
  Mighty Morphin Power Rangers - The Movie
  Mikeneko Holmes no Kishidou
  Mini 4 Boy
  Mini 4 Boy II - Final Evolution
  Mini Putt
  Mini Yonku GB Let's & Go!!
  Mini Yonku GB Let's & Go!! - All-Star Battle Max
  Miracle Adventure of Esparks - Ushinawareta Seiseki Perivron
  Mole Mania (USA), Moguranya (Japan)
  Momotarou Dengeki
  Momotarou Dengeki 2
  Momotarou Densetsu Gaiden
  Monopoly
  Monster Maker - Barcode Saga
  Monster Truck
  Montezuma's Return!
  Mortal Kombat
  Mortal Kombat II
  Mortal Kombat 3
  Mouse Trap Hotel
  Mr. Nutz
  Mysterium
  Mystical Ninja Starring Goemon (USA), Ganbare Goemon - Kurofunetou no Nazo (Japan)
  Nada Asatarou & Kojima Takeo no Jissen Mahjong Kyoushitsu
  Nakajima Satoru - F-1 Hero GB - World Championship '91
  Namco Gallery Vol.1 - Battle City
  Namco Gallery Vol.1 - Mappy
  Nectaris GB
  Nikkan Berutomo Club
  NIV Holy Bible, The (Wisdon Tree, Unlicensed)
  Otto's Ottifanten - Baby Bruno's Nightmare (Europe), Adventures of Pinocchio, The (Prototype)
  Oyatsu Quiz Mogu Mogu Q
  Pagemaster, The
  Panel no Ninja Kesamaru
  Peke to Poko no Daruman Busters
  Penguin Wars (USA), King of the Zoo (Europe), Penguin-kun Wars VS (Japan)
  Picross 2
  Pocket Bomberman
  Pop Up (USA), Cool Ball (Europe)
  Prehistorik Man (USA), P-Man (Japan)
  Quiz Nihon Mukashibanashi - Athena no Hatena
  Rampart
  Sachen 4-in-1 Vol. 1 - Street Rider (Unlicensed)
  Sachen 4-in-1 Vol. 5 - Magical Tower (Unlicensed)
  Sachen 4-in-1 Vol. 5 - Worm Visitor (Unlicensed)
  Sachen 4-in-1 Vol. 6 - 2nd Space (Unlicensed)
  Sachen 4-in-1 Vol. 6 - A-Force (Unlicensed)
  Sachen 4-in-1 Vol. 6 - Black Forest Tale (Unlicensed)
  Sachen 4-in-1 Vol. 7 - Ant Soldiers (Unlicensed)
  Sachen 4-in-1 Vol. 7 - Dan Laser (Unlicensed)
  Sachen 4-in-1 Vol. 7 - Zoo Block (Unlicensed)
  Sachen 4-in-1 Vol. 8 - Explosive Brick (Unlicensed)
  Sachen 4-in-1 Vol. 8 - Magic Maze (Unlicensed)
  Sachen 4-in-1 Vol. 9 - Crazy Burger (Unlicensed)
  Sachen 4-in-1 Vol. 9 - Deep: Final Mission (Unlicensed)
  Sea Battle (Europe), Schiffe Versenken (Germany), Bataille Navale (France)
  Shippuu! Iron League
  Spanky's Quest (USA, Europe), Lucky Monkey (Japan)
  Splitz (USA, Europe, Japan), Uchiiwai - Kyoudaijingi no Puzzle Game (Japan Rerelease)
  Sports Illustrated - Golf Classic (USA), Golf Classic (Europe)
  Spot - The Cool Adventure (USA, Japan), McDonaldland (Europe)
  Super B-Daman - Fighting Phoenix
  Super Chase H.Q.
  Super Hunchback
  TaleSpin
  Tamagotchi (USA, France), Game de Hakken!! Tamagotchi (Japan)
  Teenage Mutant Ninja Turtles - Fall of the Foot Clan (USA), Teenage Mutant Hero Turtles - Fall of the Foot Clan (Europe), Teenage Mutant Ninja Turtles (Japan)
  Teenage Mutant Ninja Turtles III - Radical Rescue (USA), Teenage Mutant Hero Turtles III - Radical Rescue (Europe), Teenage Mutant Ninja Turtles 3 - Turtles Kikiippatsu (Japan)
  Track Meet (USA, Japan), Litti's Summer Sports (Germany)
  Turok - Battle of the Bionosaurs
  Wario Blast Featuring Bomberman! (USA), Bomberman GB (Japan)
  We're Back! - A Dinosaur's Story (USA), Baby T-Rex (Europe), Agro Soar (Australia), Bamse (Sweden)
  Yoshi's Cookie (USA, Europe), Yoshi no Cookie (Japan)

Cheats summary:
generic cheats-198
unique cheats-216
buried secrets-199
fixed generic cheats-82
unverified games-440
games with secrets-440
games with no secrets found-250
overall progress-~61% done

3 Choume no Tama - Tama and Friends - 3 Choume Obake Panic!!

(GEN) Sound test:
After the boot up, before the initial copyright screen appears, hold Up + Start, then wait for the title screen.
Source: urawaza.in

4-in-1 Fun Pak

(UNI) Easter egg:
After the boot up, starting from the second screen after the license, the program start counting the Select pressings. Press it 60 times to see a mini-gallery from the developers. The counter is reset between different intro screens, the better time to enter this cheat is the title screen.

A-mazing Tater (USA), Puzzle Boy II (Japan)

Japanese version:

(FIX) Secret passwords (added 10.05.16):
MAR10W0RLD-SFX test. Press Up or Down to select, press Left or Right to play.
KAMEMASTER-BGM test. Press Up and Down to play throught the music tracks.
ARA1HELMET-Credits.
WVMP8UXNM9-Secret extra hard level.
Source: makainyumon.web.fc2.com

Adventure Island (USA), Takahashi Meijin no Bouken-jima II (Japan)

(GEN) Stage select:
At the title screen, after a while, press Right, Left, Right, Left, A, B, A, B.
Source: gamefaqs.com

(BUR) Game genie:
066‑9BF‑E66+E46‑9AF‑4CB-Replace Stage select cheat with Area select. You could start from any sublevel or enable invulnerability.
076‑9BF‑E66+656‑9AF‑4CB-Replace Stage select cheat with Mode select. You may start any of 10 main game events, except 0A event, which is Stage select itself replaced already.

Adventure Island II - Aliens in Paradise (USA), Takahashi Meijin no Bouken-jima III (Japan)

(GEN) Secret passwords:
1984-All levels, 99 of everything.
0894-Get 99 of everything.
1231-Stage 1-1 Coastal Clash, 99 of Diamonds, 3 lives.
5915-Stage 1-1 Coastal Clash, 99 of Axes and Boomerangs, 3 lives.
7265-Stage 2-1 Bottomless Pit, 99 of Spades, 3 lives.
4416-Stage 4-3 The Desolation and 4-4 Pyramid Crypt, 4 of every item, 3 lives.
Source: gamefaqs.com

(BUR) Game genie:
There is a powerful debugging mode and menus to test various parts of the game left inside the game. Can be re-enabled by setting address 0xD430 to 8 and 0xD431 to 0 respectively. The two-digits number will appear next to the PASSWORD string. Enter a number and press Start to jump to the corresponding part of the game. Or press B to enable invulnerability. The number FF will bring the Test menu. Unfortunately, the font encoding is different here from the rest of the game, so you can't see an actual text without additional hacking.
Source: tcrf.net

Adventures of Lolo (USA), Lolo no Daibouken (Japan)

All versions:

(UNI) Easter egg (added 27.08.18):
While ending credits is displayed, press A or B to increase or decrease the amount of fireworks on the backgrounds. Minimum is 1, maximum is 10.

(FIX) Stage solution:
During the game, do not press any buttons for 1 minute in the Japanese version or 1.5 minutes in the US version to get Lolo to fall asleep. Wait for another 30 minutes in the Japanese version or just 5 minutes in the US version and then the message window "WHAT AN IDEA!" will appear prompting you to "execute flash of idea". Agree and computer will show you how to solve current puzzle. To see this hint again you need to wait one more time.
Source: gamefaqs.com

Japanese version:

(GEN) Centryland cheats:
At the Centryland screen press one of the following sequences to get a corresponding effect.
Select, B-Sound test.
Select, Select, B-Stage select.
Source: gamefaqs.com

(BUR) Game genie (added 27.08.18):
010‑51B‑2A2-Re-enables debugging feature. Before the level starts, while program is waiting for pressing any button, with this code press Start a number of times corresponding to the desired effect then press any other button.
1 time-Play previously recorded replay data.
2 times-Begin the game with recording of replay data.
3 times-Play hardcoded replay data to completely solve current level.
4 or more times-Complete current stage instantly.

Adventures of Rocky and Bullwinkle, The

(UNI) Secret message:
In the first level, stand on top of one of the 6 "Frostbite falls" poles, then press Up + B + Select + Start to change the signs to one of the corresponding developers names: "KEVIN", "KATHY", "MARK", "GLEN", "DAN" and "TAK TAK TAK". The effect of this is permanent, even if you lose a life, all "Frostbite" tablets will display the last name you uncover.

Aerostar (USA), Aero Star (Japan)

(UNI) Super hard mode:
Complete the game on the Hard mode. At the screen with "THE END" hold Select and press Start. A message "CHALLENGE SUPER HARD MODE" will appear. This cheat is working in the Japanese version, but there are no text due to bug. However it can be fixed with the Game genie code 3CF‑808‑E6A.

(BUR) Game genie:
FAD‑C8E‑E65 (for the Japanese version)
FAD‑DDE‑E65 (for the US version)
-Re-enables "STGAE SELECT" (yes, with wrong spelling) cheat. At the title screen, hold Select, then press Start.

After Burst

(GEN) Self destruct:
On pause, press A + B.

(UNI) Extra 255 lives in 1P VS mode:
At the title screen, put cursor to "PASSWORD", hold Down, then additionally hold Left + A + B.

(GEN) Secret passwords:
19640813-Stage select. The password is a clearly someone's birthday.
Source: urawaza.in, makainyumon.web.fc2.com

Akazukin Chacha

(FIX) Secret passwords (added 11.08.16):
あかいかみのまほうつかい-Easter cutscene with some character, then return to the title screen. Seems does nothing.
ちかにひみつのめいろあり-A Special Birthday Party dungeon. You'll start at the empty town, find a hole in Laboratory, play this special dungeon and find a birthday party room, following with the Staff roll.
Source: urawaza.in, makainyumon.web.fc2.com

Aladdin

(FIX) Level skip (added 04.05.16):
Pause the game, then press A, B, B, A, A, B, B, A. This is the only cheat for the Game Boy on pause, the same as in the NES version.
Source: gamefaqs.com

Alien vs Predator - The Last of His Clan (USA), Alien vs Predator (Japan)

(UNI) Level skip (added 05.05.16):
During the game, press Select to enter the Weapon menu, then press Up, Up, Down, Down, A, B, A, B. Press Select again to complete current level instantly. This only work up to level 6.

All-Star Baseball 1999

(UNI) Scores edit mode (added 06.05.16):
Choose any game mode, when the "Team Options" menu is displayed (no matter if you enter this menu before the game, or during the game by pressing Start), then press Up, Down, Left, Right, Up, Down, Left, Right plus any other button to complete the sequence. A sound will confirm correct code entry. Now, start a game in any mode, enter the "Team Options" menu by pressing Start and enter the "Scoreboard". By pressing Left or Right choose current inning, press Up to increase scores of upper team, or Down to increase scores of bottom team. Also, for the game modes "Playoff" or "Season", when you quit with the higher scores than your opponent, you'll instantly win a current game and the result will be saved in the password as well, as against the normal game without cheat, which is threated quitting as a loosing current game all the time, not mater what you current score is. Repeating this process you can win the entire game in no time.

Amazing Penguin (USA, Europe), Osawagase! Penguin Boy (Japan)

(FIX) Secret passwords (added 08.05.16):
To enable these secret passwords, at the title screen hold Left + A, then enter the Password entry screen.
A0A0A0 (for the Japanese version)
101010 (for the US version)
-Enables invulnerability.
F0F0F0 (for the Japanese version)
303030 (for the US version)
-Stage select. There are two numbers appear right to the "START" option at the title screen. You can select any of 40 level.
B0B0B0 (for the Japanese version)
505050 (for the US version)
-Sound test. Select between music and sfx by press B, use D-Pad to select sounds, press A to play.
Source: makainyumon.web.fc2.com

Amazing Spider-Man, The

(BUR) Game genie (added 09.05.16):
633‑6DF‑7F0+B53‑6CF‑6E9+CD3‑6BF‑5D4-Re-enables the Stage select after the title screen. Valid values are 0-7. Use Left or Right to select, press A to play.

America Oudan Ultra Quiz

(GEN) Easter egg (added 12.08.16):
At the title screen, press B + Select to make the animated plane's picture little bit smaller. The meaning of this is unknown, but there are no other effects of this.
Source: makainyumon.web.fc2.com

(GEN) Mini-game instant win (added 18.05.16):
After the qualify stage, when you play the Rock-Paper-Scissors mini-game in Narita Airport, hold Down + Select + Start before or immediately after A is pressed to instantly win the current round.
Source: makainyumon.web.fc2.com

America Oudan Ultra Quiz Part 2

(UNI) Qualify quiz hint (added 19.05.16):
Hold Down + Right + A + B + Select before the title screen appears, either at the game start-up of after the game over screen. Now, in the quailfy quiz event (during the flight from Norita airport to USA) you can hear if you answer correct or incorrect, as against the regular game mode with completely silent answering in this event.

(BUR) Game genie (added 19.05.16):
012‑9FF‑E6A-Enables a couple of debug features. First, this will skip the starting qualify events and jumps directly to the main game map. Also, in addition to extra variables display at some game events, it will add two more button combinations to hold before the title screen appears, the same way as for working cheat.
Hold Up + Left + B + Select + Start to see all the 3-answer questions after the game start.
Hold Up + Right + B + Select + Start to see all the yes/no-answer questions correspondingly.

America Oudan Ultra Quiz Part 3 - Champion Taikai

(UNI) Secret passwords (added 20.05.16):
There are a special mode in this game: "Champion Taikai", which asking you a passwords to access it. It seems, they are released during some kind of competition in Japan and maybe well known there.
ジャストめっと-HAWAII event warp.
ジャストみっと-GAME event warp.
ジャストもっと-ROCKY event warp.
アメよこクイズ-"RAIN OF QUIZ" game.

(BUR) Debug passwords (added 20.05.16):
The password system mentioned above were also used for debugging purposes at the developement stage. The password list contains 28 passwords, only 4 are used in game, the rest is disabled. Using the Game genie code 01F‑FCC‑E6A you may re-enable them, so all following passwords will be available. It includes most of the ingame events as well as debug-only routines and sound test.
まるばつ-type 2 quiz debug
さんたく-type 3 quiz debug
じゆうのめがみ-type 1 quiz debug
なりた-NARITA event
グランド-GRAND CANYON event
じらい-GAME event FIELD RUN mini-game
サンフラン-SAN-FRANCISCO event
チキン-GRAN CANYON event RACING mini-game
ビス-BOSTON event
ヘルス-BOSTON event MOTO mini-game
マイ-MAIAMI event
タコ-MIAMI event POT mini-game
ニュウ-NEW-YORK event
チュウンサン-HAWAII event FIELD mini-game
チュウンシ-HAWAII event TRIVIA mini-game
かない-ON THE PLANE event
サメ-SAN-FRANCISCO event FISH mini-game
スケエト-ROCKY event SKATE mini-tame
エンド-Ending
チャネ-Winning slideshow
おと-Sound test
ずる-Always win
アイキュウ-+ 48 iq (used to see all endings for IQ=0/40/80/120)
ドオム-DOME event

America Oudan Ultra Quiz Part 4

(GEN) Flight Quiz Hint (added 10.01.17):
At the beginning of the game, there is a qualify quiz during flight from the Norita airport to USA. You were asked 20 questions, but there are no buzzers for the answers results. But, if you notice, there a small character at the middle-top of the screen. When you answers, he raise its right hand if answer is correct and the left hand in other case, so you may know for sure if the answer correct or not.
Source: urawaza.in

(FIX) Debug passwords (added 10.01.17):
The password system consists of 2 rows of 3 characters, there are 6 different characters. Let's number them from 0 to 5:
0 - "rock"
1 - "scissors"
2 - "paper"
3 - "O"
4 - "X"
5 - "right arrow"
The default password on the password screen is:
0,1,2
3,4,5
If you press A, you will increase the character index, and decrease if press B.
Now, the regular passwords are depending on the name you entered before the game and difficulty setting, to restore the game with a password you must enter the correct name for it first and set the correct difficult.
There are a set of debug passwords for the "ULTRA QUIZ" mode only and not depending on the difficulty settings, which allows you to access every single event in the "ULTRA QUIZ" game, excluding maybe the ending. To use them you must enter the special player's name: "TOMY". If you enter this name at the beginning of the game, you'll get the same debug passwords, while moving to the next stage, but not all of them. The complete set of debug passwords is in the table below:
5,5,5
5,3,1
-hawaii event
3,3,4
1,2,5
-alligator battle
5,4,3
4,4,1
-haunted houses
1,1,2
4,4,3
-baseball second chance
5,5,2
2,2,2
-crane machine
1,1,4
5,5,5
-basketball
3,4,3
4,3,4
-catch chicken
5,1,5
0,5,2
-rock-paper-scissors
2,3,5
5,2,5
-museum
5,3,0
3,3,3
-skiing
0,5,4
0,5,0
-balloon fight
1,2,5
1,2,5
-shooting range
2,3,4
3,4,2
-tv-show
3,3,3
3,3,3
-flight quiz
Source: urawaza.in
0,0,2
2,2,5
-title screen (hanging the game)
5,2,2
1,1,3
-continue screen

Amida

(UNI) Debug menu:
Hold A + B + Select then reset the console. At the white screen press Right, Left, Up, Down.

Animal Breeder

(BUR) Game genie (added 26.05.16):
0C1‑1BE‑E6A-Re-enables the Message debug mode at boot up.

Animal Breeder 2

(UNI) Any creature select (added 28.05.16):
At the title screen, press Right + B. A sound will confirm correcct code entry. Now, start a new game and you'll be able to select any creature to grow instead of 8 predefined characters.

(UNI) Full creature library (added 28.05.16):
At the title screen, press Left + B + Select. A sound will confirm correcct code entry. Now, during the game you'll be able to see any character's info in the library.

Animaniacs

(GEN) Secret passwords (added 31.05.16):
A numbers represents one of the characters: 0 - empty, 1 - Yakko, 2 - Wakko and 3 - Dot
0,1,2
3,3,3
0,1,1
-Level Skip. Pause the game, then press Select.
0,0,3
3,3,2
1,1,1
-Unlimited Lives.
0,1,3
1,3,3
1,3,1
-Unlimited Energy.
0,1,3
2,3,3
1,0,1
-Unlimited Time.
0,3,3
3,3,1
1,1,1
-"Negativ Cheat". Makes two midbosses of the Stage 2 very difficult, increasing its projectiles throw rate half of the minimum threshold.
Source: Factor 5

Another Bible

(BUR) Game genie (added 01.06.16):
C8A‑D28‑C4D-Re-ebanles a debug cheat. At the title screen, first select one of the debug modes described below by pressing Select.
A number of pressings corresponds to the desired function and wrapped around 8, but actally different modes are 5.
When done, press Up, Down, Left, Right, B, B, Up, Down. A sound will confirm correct code enrty. Now during the game use selected options to debug various parts of the game.
All debug modes uses different set of debug flag bits, but the bit 7 is set for all modes:
Function 0-Bit 7 is set (default).
Function 1-Bits 7 and 2 are set.
Function 2-Bits 7, 2 and 0 are set.
Function 3-Bits 7, 2, 1 and 0 are set.
Functions 4-7-Bits 7, 3, 2, 1 and 0 are set.
The following list describes the meaning of each bit:
Bit 7-Commong debug features in all game modes:
In Map mode-Start - switch to Town mode.
Select - next map.
Down + Select - previous map.
In Town mode-Start - switch to Map mode.
Select - next town.
Down + Select - previous town.
In Battle mode-Start - skips the battle
Select - next location background.
Bit 3-All items in any shop.
Bit 2-Skip enemy move in Map mode.
Bit 1-Extra 68000 gold at the beginning of the new game.
Bit 0-All characters at the biginning of the new game.

Aoki Densetsu Shoot!

(FIX) Secret passwords (added 02.06.16):
Every character in the password has an index. The first character Kenji has index 0, the last character Kazumi has index 12. The default state of password is 00,00,00,00. To enter these passwords, you need to set it to default state and press Up a corresponding number of times to set the particular character in corresponding position.
00,09,08,02-Secret team match (Level 5)
12,12,12,12-Slideshow of the Kazumi character's cutscenes.
Source: urawaza.in

(BUR) Game genie (added 02.06.16):
The password system has 5 more "Slideshow" passwords for diferent characters, but they are disabled by setting the incorrect values to the password list. By restoring them using following Game genie codes you may see rather unfinished or maybe boring thus disabled slideshows.
093‑E8B‑6E7-Use password "09,09,09,12".
003‑ECB‑6E7-Use password "00,00,00,12".
083‑F0B‑6E7-Use password "08,08,08,12".
0B3‑F4B‑6E7-Use password "11,11,11,12".
003‑FCB‑6E7-Use password "00,09,08,12".

(BUR) Game genie (added 02.06.16):
05F‑DCE‑E66+05F‑F0E‑E66-Re-enables two hidden menu items at the title menu. One is for Cutscenes debug menu (using the same text as for Settings menu). Another is for Field viewer, but with incorrect CHR data setting.

Arcade Classic - Battle Zone & Super Breakout, Super Breakout (Single game cart)

(UNI) Cheat sequences (added 30.06.16):
Any of this cheats can be entered any time in any game either on the title screen or during the game. After entering the sequence press Select to activate a corresponding cheat.
A, B, A, B, A, B, A, B-Show a smiling baby picture with a funny sound.
B, A, B, A, B, A, B, A-Show something creepy with a creepy sound as well.
Up, Down, Left, Right, Up, Down, Left, Right-This has effect in the Battle Zone game. During the game, as you scroll the background, a message will appear:
"AS YOU FIND WHAT YOU NOW SEEK IS MORE INLAND AND WHAT YOU ONCE KNEW WAS SOLID IS JUST SHIFTING SAND".

(UNI) Sound editor (added 30.06.16):
At the title screen of the Super Breakout game, press Up + A + B. You'll be able to set any sound registers parameters and play it by press Start.

Arcade Classic No. 1 - Asteroids, Asteroids (Single game cart)

(GEN) Invulnerability (added 04.06.16):
At the game mode selection screen, press B, A, A, B, A, B, B, A, B, B, A, B, B. This cheat also work on Arcade Classic version.
Source: gamefaqs.com

Arcade Classic No. 3 - Galaga, Namco Gallery Vol.1 - Galaga

(UNI) Free dual ship (added 29.06.16):
During any Challenging Stage after Stage 32, any time pause the game, then quickly press Down, Up, A, Left ("DUAL") to get an instant dual mode ship. The pause between keypress must be less than 1/4 second.

Arcade Classic No. 4 - Defender

(UNI) Skip to hi-score (added 29.06.16):
At the title screen, hold Left, then press Select to skip to the hi-score display immediately without need to wait.

(UNI) Continue (added 29.06.16):
Enter the Options menu, put cursor to the "EXIT" option and press Left 40 times until you hear a sound. Now, instead of game over during the game you'll get to the Continue menu. Continues are unlimited.

Arcade Classic No. 4 - Joust

(UNI) Skip to hi-score (added 29.06.16):
At the title screen, press Left + Select to skip to the hi-score display immediately without need to wait.

Aretha II

(GEN) Easter egg (added 28.02.17):
At the title screen with the bubbles floating, hold either Left or Right to control the direction of the bubbles flow.
Source: urawaza.in

Aretha III

(GEN) Sound test (added 04.02.17):
One of items that can be found in this game called "Aretha CD" and when used enables a Sound test. Investigate, where is to buy this particular item.

Asmik-kun World 2

(GEN) Secret passwords:
RDEST???-Even if the passwords for Stage 4 is written by the game, they aren't work by itself, only available with this additional password, but other passwords are disabled instead, when it is used, with one exception (see below).
EVE?????-Event viewer.
MAP?????-Debug menu. The only password available when using an extra password RDEST??? as well.
SOUND???-Sound test.
Source: tcrf.net

Asterix

(GEN) Cheat menu (added 03.06.16):
During the game press Start to pause it. Then enter following code Up, Up, Up, Up, Up, Up, Up, Up, Down, Down, Down, Down, Left, Left, A, B, Right, Right, Right, Right, Right, Right, Right, Right, Left, Left, Left, Left, Up, Up, B, A. A sound will confirm correct code entry, then press Start and game will return to the title screen with extra "cheat" menu item.
Source: gamefaqs.com

(UNI) Invulnerability (added 03.06.16):
Input the Cheat menu code as described above, but before pressing Start to return to the main menu, hold Up + Right + A + B + Select. Start a new game with any cheats as you wish and press Start to pause it again. Enter the Cheat menu code one more time. A sound will confirm correct code entry. Press Start to unpause the game. From this point you will be fully invulnerable.

Asterix & Obelix

(GEN) Stage select (added 03.06.16):
At the title screen, press Left, Left, Left, Left, Right, Up, Up, Down, Select, Right, Right and listen for a sound. A Stage select will now be added to the Options menu.
Source: gamefaqs.com

Atomic Punk (USA), Bomber Boy (Japan), Dynablaster (Europe)

(UNI) Sound test (added 05.06.16):
In the GAME A (BOMBER BOY for the Japanese version) mode, at the Stage select screen, enter MY TOWN with Right + A + B + Select held. Note: when you press Right, the selection on the map is changing, so you can either press Right first and hold it when stop on MY TOWN and then hold the rest of the buttons, or just put cursor to the previous position to MY TOWN before holding all the buttons.
Source: tcrf.net

Attack of the Killer Tomatoes

US version:

(GEN) Credits (added 06.06.16):
At the title screen, press B to see a credits. There is no such function in the the Japanese version.

(UNI) Cheat mode (added 06.06.16):
At the title screen, hold Up + Select, then press B, B, A. A title music should stop as well as the tomato face animation. Now, press A a number of times corresponding to desired level number, the title music will restart every time you press a button. Or press B once (hear a sound) to enable invulnerability (flashing mode). Press B one more time (hear another sound), to additionally get an infinite lives and all items at start. Althought this is not disables invulnerability, this will disable flashing. Press Start to begin a game with a selected cheat options at the desired level.

Japanese version:

(BUR) Cheat mode (added 06.06.16):
The the Japanese version seems simply is an early version of this game, so they just didn't coded the cheat input at all. But, there are the same variables controlling the cheat states already coded and working. Set the RAM address $C677 to non-zero value to enable invulnerability, additionally set $C676 to non-zero value to enable infinite lives and get all items as well.

Avenging Spirit (USA, Europe), Phantasm (Japan)

(GEN) Expert mode (added 07.06.16):
This code is unlockable in the Japanese version. If you beat the regular game, there will be a screen with instructions how to enable an Expert mode. If you beat the game on the Expert mode there will be additional ending screen. Both screens were removed in the US version, but the Expert mode still can be enabled the same way: at the title screen, press Up + A + B. A sound will confirm correct code entry in both regional versions. Additionally in the Japanese version, a message "EXPERT" will appear at the bottom-left corner of the title screen.
Source: gamefaqs.com

(GEN) Bad ending (added 07.06.16):
At the title screen, press Down + B + Select. A bad ending happens if you beat the game as a regular haunted character.
Source: gamefaqs.com

(UNI) Good ending (added 07.06.16):
At the title screen, press Down + A + Select. To get a good ending normally you must find three keys hidden in various levels and open the door near the end of the last stage where your girlfriend is imprisoned.

(UNI) Easter egg (added 07.06.16):
During the intro cutscene, hold Up before the 4th screen with a screaming guy appears. The text line "ガチョーン" will appear on the screen in both the USA and the Japanese versions, which means this is just a leftover from the Japanese version not removed in the US version. The text line is an obsolete Japanese word to express shock (gaccho~n).

Bakenou TV '94

(UNI) Race cheat (added 15.06.16):
At the title screen, press Up, Up, Up, Up, Up, Up, Down, Down, Up, Up. Start a new game and you'll hear a different sound if cheat is enabled. Don't know exactly, what it's doing, but every race results will be slightly different from the regular ones (higher values in the results lists, etc.). Need investigation.

Bakenou V3

(UNI) Race cheat (added 15.06.16):
At the title screen, press Up, Up, Up, Up, Up, Up, Down, Down, Up, Up. Start a new game and you'll hear a different sound if cheat is enabled. Don't know exactly, what it's doing, but every race results will be slightly different from the regular ones (higher values in the results lists, etc.). Need investigation.

Bakuchou Retrieve Master

(BUR) Game genie (added 15.06.16):
201‑71F‑91E-Re-enables the complex debug menu at game boot.
Source: tcrf.net

Bakuchou Retsuden Shou - Hyper Fishing

(GEN) Cart RAM clear (added 23.02.18):
Before power the console on, hold Up + Left + B.

(GEN) Ending (added 23.02.18):
At the data load screen, choose the "LOAD" option, while choosing a data slot hold Up + Right + Start and press A.
Source: urawaza.in

(UNI) Catch screen cheats (added 26.02.18):
All these test are enabled the same way. During the game, select any empty map tile, press A and choose a second option in the menu "ちょうか" ("A catch"), then select an option "かこのきろく" ("Previous records"). Press Start a number of times particular to desired effect (see the table below) and press A.
5 times-Sound test.
Source: urawaza.in
8 times-"Live well" viewer. View fish pictures and info in the "ライブウェル" ("Live Well") list if any. Note, scenarios for Stages 5, 8, 9 and 10 does not have such events, so you'll see a corresponding warning message instead.
9 times-Previous Records viewer. View fish pictures and info in the "かこのきろく" ("Previous records") list if any.

(UNI) Debug mode (added 23.02.18):
At the Star-Fish logo, quickly press Select, Up, Down, A, Left, Start. When the screen fades out, a message "DEBUG MODE / DEVELOPMENT STUFF ONLY" will be displayed. At this screen, hold Select and wait until the "DEBUG MENU" screen appears. You can access this menu during the game by holding Select at the beginning of some events or while in transition between game screens. This also enables the debug info display in the Fishing mode after you leave "DEBUG MENU". In "DEBUG MENU" you can to access a Sound test, characters/battle/land editors, begin the game from any stage, clear CRAM data, view all game messages, or level up any character.
Other debug features (incomplete list):
Any time during the game, hold Select and press Start to pause it, press Start again to unpause.
At the Stage name screen, hold Start + Down before the screen fades out to skip the cut-scene.
At the action select menu, before selectin the "MOVE" option hold Select to be able to move any available zone on the current map.
During the NPC turns, hold Select to speed-up the process.
During Casting mode, hold Start before either throw, bait display or fish catch to instantly catch a Bass. Note, even with this debug trick you couldn't catch anything with wrong equipment, bait or low experience.
At the Casting techniques selection, put cursor to the desired option with Down and hold it, then press Start. Use Left/Right to choose technique level up to max possible.
During Reeling mode, press Start either with one of D-Pad buttons held or not to begin one out of 5 incidents which usually occurs randomly depending on the environment settings.At the game field, hold Select, then press one of the following buttons to get the corresponding effect.
A-If character is selected, the unit's general and private indexes will be displayed. If ground tile is selected, display rivals overall statistics.
B-Displays a current event name.
Up-Enter the Catch lists editor. Choose a fish to be catched. Set its max weight up to 5,1K with Left/Right. Press A to silently update the Recent records entry for this fish or press Start to display a regular Catch screen with information about fish and experience update. The first two positions in the list are Basses, so they will go to "Live Well" list also. The second to last option is for clear all catch lists and the second one is for clear only Prevoius Records list.
Right-Show some kind of timers list depending on Bass catches.
Down-If player's character is selected, resets its "End of Turn" state.

Banishing Racer

(GEN) Invulnerability (added 15.06.16):
During the game, on pause, hold Up + Select, then press A + B. A "PAUSED" string will change to one of the messages: "Run^2" or "Jun^2", as well as the sound will be heard. This cheat works only for current level and you still may be hurt by the spikes or by the bosses.
Source: makainyumon.web.fc2.com

(GEN) Stage select (added 15.06.16):
At the title screen, hold Down, then press A + B a number of time corresponding to desired level number, for every press will hear a sound. Press Start to play. More than 15 pressings shows the ending.
Source: urawaza.in

Batman

(GEN) Sound test (added 19.06.16):
At the title screen, hold Up + Right, then press Start.
Source: gamefaqs.com

(FIX) Level and weapon select (added 19.06.16):
The Stage select mode is unlockable here. Beat the game once, then at the title screen press Start to begin a new game, but before the the title screen disappear, hold Select. Additionally, when the final message of the credits roll "THE END" appears, hold Select and wait for the title screen. This will also enable a Weapon select mode. During the game press Select to cycle between all possible weapons.
Source: urawaza.in

(UNI) Batwing shot rate select (added 19.06.16):
During the Batwing stages (3-1, 3-2), press Start to pause the game, then press B, Up, Select, A. Now, you need to input a 4-button sequence, which will be treated as 4-bit binary number, which is representing a desired shoot rate when you hold A during the game. Any buttons except A means binary 0, the A button means binary 1. Lets use for the binary 0 the B button, then we can write down all possible valid codes in the table below. So, the best complete button code of this pause cheat for fastest shot rate is B, Up, Select, A, B, B, A, A. Now, just unpause the game.
B, B, B, B-Invalid value, set to shot rate 15 (slowest) instead 0.
B, B, B, A
B, B, A, B
-Invalid values, set to shot rate 10 (default, used by the game) instead 1 and 2 correspondingly.
B, B, A, A
B, A, B, B
B, A, B, A
B, A, A, B
B, A, A, A
A, B, B, B
A, B, B, A
A, B, A, B
A, B, A, A
A, A, B, B
A, A, B, A
A, A, A, B
A, A, A, A
-All valid values from 3 (fastest) to 15 (slowest) correspondingly.

Batman - Return of the Joker

(UNI) Secret bonus (added 18.06.16):
At the title screen, press Left + B + Select. The game will immediately start with a different starting sound, rather than a regular bat wings sound. Now on every boss stage, when the player's health drops below the 3 points, but the boss still has more than 16 health points, the friendly support character will fly over the screen dropping up to 4 heart bonuses. Hovewer, this bonus may be triggered only once for each boss.

Batman - The Animated Series

(GEN) Stage select (added 21.06.16):
This cheat is unlockable after a completing the game. Then just press Select at the title screen to enter the regular options menu.
Source: gamefaqs.com

Batman Forever

(GEN) Cheat menu (added 22.06.16):
At the difficulty selection screen, press Up, Right, Down, Left, Up, Left, Down, Right. You'll be able to enable all ammo, no damage modes and select any stage to begin the game.
Source: gamefaqs.com

(FIX) Credits (added 22.06.16):
At the difficulty selection screen, press Up, Up, Up, Up, Down, Down, Down, Down.
Source: gamefaqs.com

Battle Arena Toshinden (USA, Europe), Nettou Toshinden (Japan)

(FIX) Special cheats (added 24.06.16):
All cheats are entered at one of the three screens: the Takara logo, the Ellis opening and the title screen. Some cheats may be used only in Super Game Boy mode. When cheat is entered correctly, an unique sound for every cheat will be heard.
Where to input?|Cheat sequence|Effect|SGB only|Is it unlockable?
At the opening screen with Ellis.|Right, Left, A, B|Gaia and Sho unlocked.|No|Yes. For beating Easy mode.
At the Takara logo.|Select, Select, Select|Scorcher mode. A couple of new special attacks may be used now.|No|Yes. For beating Normal mode.
At the title screen.|Up, Up, Select, A, Down, Down, Select, B|Jet mode. Fastest movement speed for all players.|Yes|Yes. For beating Normal mode.
At the opening screen with Ellis.|Up, Down, A, B, Right, Left, A, B|Gaia, Sho, Gaia2 and Uranus unlocked.|No|Yes. For beating Hard mode.
At the Takara logo.|B, A, Left, Right, B, A, Down, Up, B, A|Text mode. View all text messages for the game.|No|Yes. For beating Expert mode.
At the title screen.|Up, Down, Left, Right, Select, A, Select, B|Both players are now CPU controlled in all modes.|Yes|No. Secret cheat.
At the Takara logo.|B, Select, A, Select, Right, Left, Down, Up|Skip tournament and instantly show the ending for any character.|Yes|No. Secret cheat.
Source: gamefaqs.com

Battle Bull

(BUR) Game genie (added 28.06.16):
209‑10D‑E6A+0F9‑11D‑E6A-Re-enables the debug mode. Gives an extra 99999999 gold, invulnerability, and enables the Stage select at the beginning of the game.

Battle City

(GEN) Stage select (added 28.06.16):
At the Stage number screen, press Up or Down to choose a level up to 32 by default. When you beat any games above, you'll be able to select it as well. Beat the game to unlock all levels.
Source: gamefaqs.com

(FIX) Cheat sequences (added 28.06.16):
All cheats are entered at the title screen. A sound will confirm correct code entry. Any number of cheats may be entered, all effects are combined.
Left, Left, B, A, Up, Down, A, Right-Start with 9 lives.
Down, Up, Up, Down, Left, Right, A, B-Unlock all stages in Stage select mode.
B, A, B, B, A, B, A, A-Start with level 3 tank.
Down, Left, Up, A, Right, Right, B, Up-Options menu. Allows you to select game speed, lives and extend mode, which determines one of two score tables for obtaining a new life.
Right, Up, A, Down, B, Left, A, B-Increase number of enemies after Stage 5 on the field at the same time up to 6 (default is 4).
Up, Up, Down, Up, Left, Right, Right, Left-Shovel power-up will use a random block.
Up, B, Left, A, Right, B, Down, A-Enables an auto-fire.
A, Down, A, Up, A, Right, B, Left-Credits, but without unlocking all stages.
Source: tcrf.net

Battle Crusher

(FIX) Special team (added 01.07.16):
At the title screen, when the "PUSH START" message is displayed, press Left, Left, Left, B, A. This cheat also work for a second player in 2-player game either via link cable or with SGB controllers.
Source: gamefaqs.com

Battle Pingpong

(GEN) Secret passwords (added 01.07.16):
1199-Stop watch minigame. This is unlockable password, given to you after beating the final game with Panda.
4989-"NEVER GIVE UP" screen display.
Source: gamefaqs.com

Battle Unit Zeoth, Jet Pack (Prototype)

(FIX) Training mode (added 04.07.16):
At the title screen, hold Down, then press A + B a number of times corresponding to the desired stage from 1 to 5. You will start a new game from the selected level with 240 hit-points instead of 8, so technically you will be invulnerable for some time. But you can't advance to the next stage playing this mode, you can play only the selected level again and again. If you press A + B at the title screen 6 times, you'll be able to see the ending. But the staff roll will be different from one you should see if you beat the game normally, containing additional programmer's message. Also, if using this cheat you'll start a new game after the staff roll with only 1 hit-point and no weapon as against the normal ending, which starting a new game with max power lazer and 8 hit-points.
Source: gamefaqs.com

Battle of Kingdom

(GEN) Stage select (added 03.07.16):
After the game is boot up, within first 5 seconds while the title screen is displayed, press Down + A + B + Select. During the game, on the map screen press A or B to skip to the next stage. Also this additionally gives to you an extra 9000 gold. Don't forget to buy come cards before entering any fight, or it will ended up with a game over.
Source: urawaza.in

Battle of Olympus, The

(UNI) Cheat mode (added 04.07.16):
During the game, press A, B, B, A, Up, Down, Left, Left, B, A. Now press B + Select to enable the free walk mode. While in this mode, press A to skip to the next location, or Start to exit this mode.

(BUR) Hidden text (added 04.07.16):
At 0x127B5 in the ROM an unused text string can be found:
BOBMA%RLEY%%
Judging from the place, where it located and its format, this may be either a default names for the Hero and Heroine or a secret names.

Beavis and Butt-head

(BUR) Game genie (added 07.07.16):
080‑A2D‑E6E-Re-enables an unused Stage select screen. You'll be able to select any level, including the Mini-game. The last unnamed option in this menu isn't working.
Source: tcrf.net

Beethoven

(UNI) Stage select (added 07.07.16):
During the game, stand still, then press Up, Down, Up, Down, A, A, Up, Down, Down, B. A small number will appear in the middle of game's HUD. Select desired level and press B. Note, that stage indexes are inverted, 0 means the last level, 5 means the first level. The number 6 means the ending screen.

Beetlejuice

(GEN) Stage select (added 07.07.16):
At the title screen, quickly press Left, Right, Up, Up, Down, Down. If you hit the wrong button or pause between two presses more than 1/4 of second, the cheat won't work until you reset the console.
Source: genhoaxer

Best of the Best - Championship Karate (USA), Kick Boxing, The (Japan)

(UNI) Credits (added 11.07.16):
At the main game menu, hold Select, then press Up. The same credits screen is shown when you beat the game.

(UNI) Secret passwords (added 09.07.16):
KUKUM000-Weaken the enemy to lowest HP.
TONY0000-Invulnerability for player.

Bikkuri Nekketsu Shin Kiroku! - Dokodemo Kin Medal

(GEN) Secret team (added 28.02.17):
At the Team selection screen, choose any team, hold Select then press A or Start. The secret 4th team (Oklahoma) will be selected.
Source: urawaza.in

(UNI) Tournament skip (added 11.07.16):
During the game, if you loose one of the first two rounds of any tournament-type competitions, the game for the 1st place will be played by CPU controlled characters. In this case you can skip this unnecessary round, just pause the game, and press Down + A + Select.

(BUR) Unused obj viewer (added 11.07.16):
During the game, pause the emulation and change $C000 and $C001 RAM addresses to $A and $0 correspondingly. This will switch the game in simple debug viewer for currently selected sprites list. This mode does not load an actual CHR data, so you can see only the sprites, loaded by the game previously. So if you enable it during one of the competitions, you may see the complete set of its sprites.

Bill & Ted's Excellent Game Boy Adventure

(GEN) Cheat sequences (added 11.07.16):
All cheats are entered at the title screen, a sound will confirm correct code entry. Cheats can be combined.
Up, Up, B, Down, Right, A-Infinite lives.
Left, Right, Left, Right, Up, A-Infinite time.
Source: gamefaqs.com

(BUR) Game genie (added 11.07.16):
9A1‑3AD‑E61+6B1‑3BD‑7F3-Re-enables an unused memory viewer function, used at the developement stage for verifying the demo recording data. The demo recording code still present in the game too, but need more effort to re-enable it back.

Bionic Commando

(GEN) Return to map (added 13.07.16):
To return back to the map screen any time during the game, press A + B + Start.
Source: gamefaqs.com

Bishoujo Senshi Sailor Moon

(BUR) Game genie (added 13.07.16):
071‑93F‑F72-Replaces the soft-reset function with a Stage select. Numbers from 1 to 4 are select levels, number 5 should select additional cheat flag, maybe invulnerability, but it is never used. Note, that due to hacky method of enabling the Stage select may cause glitches when used.

Black Bass - Lure Fishing (USA), Hyper Black Bass (Japan), Hyper Black Bass '95 Black Label (Japan Rerelease)

(UNI) Sonar mode (added 14.07.16):
At the title menu, put cursor either to the start or to the continue menu options, then press B + Select. A game will start instantly. Now, during catching seqeunces, the DEPTH/LINE parameters will display the fish position near the lure, rather than actual lure depth and line lenght. The values are in range 0.0-5.0. A higher values means that fish is closer.

Blades of Steel (USA, Europe), Konamic Ice Hockey (Japan)

(GEN) Sound test (added 15.07.16):
At the license screen in the US version, or at the Konami logo screen in the Japanese version, press Up, Up, Down, Down, Left, Right, Left, Right, B, A, B, A.
Source: urawaza.in

(UNI) Secret message (added 15.07.16):
There are a few of secret messages hidden inside the ending's staff screens. Each message assigned to its own staff screen and has unique method of revealing. Here is the complete list:
Where to find|How to enable|Effects
The "co-programmer" screen|Press Up, A, Right, A, Down, A, Left, A, then A one more time.|First, the code will show the message "HELLO!! I LOVE ??? FROM .....".
Then, if A additionally is pressed before the message disappears, there will be an ASCII heart displayed.
The "character designer" screen|Hold B, then press A.|The message "NEVER GIVE UP" will be displayed.
The second "special thanks" screen|Press A once to display the first message,
then A two more times for every next message.
|The additional 6 "special thanks" names will be displayed: "H.HATANAKA", "H.UEDA", "T.HAGIHARA", "N.KODAMA", "M.ITO", "R.GOTOU". And the final string will be "AND YOU!!".

Blaster Master Boy (USA), Blaster Master Jr. (Europe), Bomber King - Scenario 2 (Japan)

(GEN) Stage select (added 16.07.16):
At the title screen, hold A and press Start.
Source: gamefaqs.com

Block Kuzushi GB

(UNI) Stage skip (added 17.07.16):
At the title screen, press Up, Left, Down, Right, A. A sound will confirm correct code entry. During the game hold Up/Down and press Select to skip to the next/previous stage correspondingly. Also, on pause press A to manually advance to the next frame.

Blues Brothers, The Jukebox Adventure

(UNI) Stage select (added 17.07.16):
At the Titus logo screen, hold B, then press Right, Left, Up. Release all buttons, then press Select 7 times. Now, at the Stage number screen press Select to change the current level up to 17, after 17th pressing there will be the ending screen.

Bomb Jack

(UNI) Infinite lives (added 23.07.16):
During the game, on pause, press Up, Up, Up, Up, Up, Up, Up, Up, Right, Right, Right, Right, Up, Up, A.

Bomberman GB (USA), Bomberman GB 2 (Japan)

(FIX) Secret passwords (added 26.07.16):
2145-Sound test
5656-The Battle mode
4622-Start the game fully powered
Source: gamefaqs.com

Bomberman GB 3

(GEN) Secret passwords (added 26.07.16):
DEB1F7F-Boss rush mode.
Source: gamefaqs.com

Bonk's Adventure (USA), B.C. Kid (Europe), GB Genjin (Japan)

(BUR) Game genie (added 10.06.16):
009‑23E‑5D5 (for the Japanese version)-Re-enables the Stage select cheat. During the game, press B + Select. The same code present in the US version at 01:$4224, but since there are no more proper caller for this routine, it won't work correctly all the time.
010‑03F‑E6A (for the US version)
000‑03F‑E6E (for the European version)
-Switches the title to different region settings for corresponding versions.

Bonk's Revenge (USA), B.C. Kid 2 (Europe), GB Genjin 2 (Japan)

Japanese version:

(GEN) Stage select (added 14.06.16):
At the title screen, press Down + A + B + Start.
Source: urawaza.in

English versions:

(BUR) Game genie (added 14.06.16):
01A‑CAB‑E6A-In all English versions the Stage select mode were were disabled, but can be reenabled somehow with this code.

Booby Boys

(UNI) Ending (added 27.07.16):
Complete any of the game Worlds, after beating a boss there is a screen with some congratulation message instead of the Stage complete screen. This screen will stay untill you press Start to continue. Press Up + Right + Select to jump directly to the Ending screen. Note, in this case your progress will be lost.

Boomer's Adventure in ASMIK World (USA), Teke Teke! Asmik-kun World (Japan)

(FIX) Secret passwords (added 27.07.16):
All passwords here except the last one are not secret, but this is exactly full set of passwords and its destinations.
AXOLOTL-Level 8 (1st Boss)
BLUTEN-Level 9 (2nd World)
CHIMERA-Level 16 (2nd Boss)
DEWLAP-Level 17 (3rd World)
ELYTRON-Level 24 (3rd Boss)
GILA-Level 25 (4th World)
HYDRA-Level 32 (4th Boss)
IBEX-Level 33 (5th World)
JEDOCH-Top of the Tower
KURZER-Level 24 (Descent)
MINORCA-Level 23 (Descent)
PANGOLIN-Level 16 (Descent)
REMORA-Level 15 (Descent)
TROKEN-Level 09 (Descent)
SCARAB-Level 08 (Descent)
ZAHNBELA-Final Boss
ANCIENT-Stage Select
Source: gamefaqs.com

Boxxle (USA), Soukoban (Japan)

(FIX) Credits (added 28.07.16):
At the title screen, press Up + A + B + Select.
Source: gamefaqs.com

(FIX) Special passwords (added 28.07.16):
Q♠MY (for the US version)
さみくち (for the Japanese version)
-Special hidden level 1.
Q♠X4 (for the US version)
さみたの (for the Japanese version)
-Special hidden level 2.

(UNI) Secret passwords (added 28.07.16):
YLM? (for the US version)
かわらふ (for the Japanese version)
-View all cutscenes in row and then the credits.
3947 (for the US version)
とみさわ (for the Japanese version)
-Music test.

Boxxle II (USA), Soukoban 2 (Japan)

(UNI) Secret passwords (added 28.07.16):
JYBD (for the US version)
おちあい (for the Japanese version)
-View all cutscenes in row and then the credits.
XK5R (for the US version)
たかはし (for the Japanese version)
-Music test.
?♠Q? (for the US version)
とみさわ (for the Japanese version)
-Credits.

Bram Stoker's Dracula

(UNI) Stage skip (added 30.07.16):
At the Stage number screen, before the game start, start to press B as fast as you can. If one of the pressings occurs right in time, when to Stage number screen is about to disappear, then the current level will be skipped instantly. If you skip the last level, you'll start from the beginning again. The reason why this doesn't work all the time even with autofire option in emulator is because the button pressing trigger lasts just one frame. If button is held for more than one frame, this trigger is resetting. The game checking exactly the pressings trigger, not the helds one. Probably this is just a debug leftover, but maybe just a reward cheat for fastest fingers. ;) To make this cheat reasonable, use Game genie code 9E4‑29F‑914. With this, the skip button should be held instead and will work all the time.

BreakThru!

(UNI) Stage skip (added 30.07.16):
Choose "Options" from the title menu and enter "CREDITS" there. Now press B, A, A, B, B, A. Every single press skips to the next credits screen, and at the "SPECIAL THANKS TO" (6th screen) you'll hear a sound. Now, start a new game. Any time, hold Start and press B/A to skip to the next/previous level accordingly. This also pauses the game, so you must unpause it before continue. On the emulator you can hold auto-fire B/A buttons and then shortly press Start to avoid unnecessary pausing.

Bubble Bobble

(UNI) Password generator (added 01.08.16):
There are two types of passwords can be accepted by the game. The regular passwords generated by the game itself set the maximum level number, flags for collected items and an Expert mode flag. Also, there is a secret password type, uses a different generation method and doesn't affect the level number. Instead it set the power-up flags which is used for enabling a regular in-game power-ups before starting a new level. As against the power-ups picked up during the game, the effect of these passwords is permanent even after continue. Enable "Power-up" checkbox to generate a special password. When entered, a message "POWER UP!" will be displayed with a different sound, but no return to the title screen. You need to exit the password screen first and then start a new game to enable selected power-ups. Also, with one of the special flags you can start with 9 lives instead of 3. Note, that you can't have all power-ups and 9 lives at the same time, instead if all flags are set, when exit form the password screen you'll get the Sound test mode. Also, the special pass should have at least one flag raised, if all flags are clear, the password is invalid.
Level:Power-up:
Magical Cup:Speed:
Magical Jewel:Shot range:
Magical Crown:Shot rate:
Expert mode:9 Lives:
Password:


Bubble Bobble Part 2 (USA), Bubble Bobble Jr. (Japan)

(BUR) Game genie (added 02.08.16):
019‑D0D‑E6A (for the US version)
019‑C6D‑E6A (for the Japanese version)
-Re-enables the debug Stage select and Sound tests screens. During the game, press Select, then Start to enter this mode. A number in the middle of the screen represents the stage index as well as music index. To play music, press A, to start from the selected level press Start. Note, that so-called "Stage select" password for this game known before actually is a regular password with stage number above the valid game limits. Any valid game password threated by the game as a Stage select from 1 to level number encoded in the password itself.

Bubsy II

(GEN) Invulnerability (added 02.08.16):
Pause the game, then press Up, Up, Down, Select, A, A, B, B.
Source: gamefaqs.com

Burai Fighter Deluxe

(UNI) Easter egg (added 03.08.16):
Beat the game either on Ace or Ultimate difficulty to get a graphics ending. Press A to make the character to turn face to the screen.

(FIX) Secret passwords (added 03.08.16):
All secret passwords are staring from Stage 1 on Eagle (Easy) difficulty. The Japanese version passwords are most likely the developer's names, but in the western versions due to removal of letters turns gibberish.
HGDM (for the US version)
HIDE (for the Japanese version)
-99 Lives.
KHDC (for the US version)
KADO (for the Japanese version)
-All weapons.
Source: gamefaqs.com

(BUR) Game genie (added 03.08.16):
015‑52E‑E6A (for the US version)
01D‑95F‑E6A (for the Japanese version)
-Re-enables the Invulnerability cheat. At the Stage number screen hold Up + Left + B before press A or Start.

Bust-A-Move 2 - Arcade Edition (USA), Puzzle Bobble GB (Japan)

(GEN) Extra puzzles (added 05.08.16):
At the title screen, press A, Up, B, Down. A small character will appear at the bottom-right corner of the screen. This cheat is unlockable after completing the regular puzzle mode of the game.

(UNI) Extra continues (added 05.08.16):
Enter Options menu, put cursor to the Credits option, then press Left, Right, B, A, A, B, Right, Left. A small countdown timer will appear at the top-right corner of the screen. Now press A as fast as you can. Every 10 pressings will give you one extra continues up to 29 maximum. You have only 29 seconds.

Bust-A-Move 3 DX

(GEN) Extra puzzles (added 05.08.16):
At the title screen, press A, Up, B, Down, Up, Left, B, Right. A small character will appear at the bottom-right corner of the screen. This cheat is unlockable after completing the regular puzzle mode of the game.

(UNI) Extra continues (added 05.08.16):
Enter Options menu, put cursor to the Credits option, then press Left, Right, Left, Right, B, A, A, B, Right, Left, Right, Left. A small countdown timer will appear at the top-right corner of the screen. Now press A as fast as you can. Every 10 pressings will give you one extra continues up to 29 maximum. You have only 29 seconds.

Cadillac II

(UNI) Pre-defined card stack (added 08.08.16):
In a single-player game, at the cards shuffling screen, quickly hold Up + A + Start before the shuffling animation is started, and release all the buttons after it started. This makes the cards stack be the same for any level.

Captain Tsubasa J - Zenkoku Seiha e no Chousen

(GEN) Secret passwords (added 10.08.16):
HIDE-Hidden UFO mini-game.
Source: makainyumon.web.fc2.com

(BUR) Game genie (added 10.08.16):
622‑08F‑6EF-Debug mode enable. After boot up, you'll see a number representing one of the internal game handlers. Some of the game handlers are for debugging and can't be accessed during the game:
2 - Character expressions veiwer
9 - CHR data/tilemaps viewer (note, that only leftmost index used here, actual index should consist of two parts:
tile data index and bg map index in one hex value,
this screen however displays only decimal indexes so if idexes doesn't match, you will see rather garbage instead of an actual picture)
18 - Sound test
19 - Animations viewer
Press A to enter the selected game handler or press Start to return to the normal game.
642‑0EF‑6E7-Prototype mode enable. In this mode after playing one round in any mode the game will show you an advertise screen, then return to the title screen.

Captain Tsubasa VS

(GEN) Secret passwords (added 16.08.16):
The only way to play VS CPU game is to write down one of two predefined passwords. The game itself doesn't have an option to show the password in this mode, so this is most likely were some kind of competition passwords available only in Japan.
もりさきもつかつてね-VS CPU mode regular team select.
すりいもでるのよ-VS CPU mode junior league team select.
Source: urawaza.in

Card Game

(FIX) Game select menu cheats (added 13.01.17):
All cheats must be entered at the game select menu in 1P mode. Hold Select, then enter Right, Down, Left, Up, Down (the common part of all cheats). Do not release Select, then complete the code with one of the sequences from the table below. Each cheat upon copleting the D-Pad buttons input will point to the corresponding game, so you automatically will start a corresponding game, which affects the code in question. Note, that cheats may be combined and will work until you reset the console.
Right, Start-Ending
Source: urawaza.in.
Right, Up, Left, Start-In a Poker game, now you can do discarding of your cards up to 5 times in row per turn instead of only one discard. Hold Select before completing the discard process to skip to the next turn instantly.
Right, Up, Start-In a Black Jack game doubles any pay-out even if you has a draw.
Start-In a "U.S.A" game, when players hand has only one card, code prevents from "skip", so you will have one card always during the CPUs turns.

Castelian (USA, Europe), Kyoro-chan Land (Japan)

European version:

(UNI) Infinite timer (added 17.08.16):
Before powering the console, hold Down + B. At the title screen, release all buttons and hold Up + Right + A, then press Start. This cheat didn't present in other game versions.

Japanese version:

(GEN) Secret passwords (added 17.08.16):
At the title screen, press B to enter the password screen, now input one of these passwords to access the desired level. The passwords are given to you after completing the corresponding stage, so they aren't secret actually, but there is no password systems in any other versions of the game.
TRF-Stage 2
GZB-Stage 3
PKW-Stage 4
HQJ-Stage 5
BLV-Stage 6
WPT-Stage 7
RPR-Stage 8

Castle Quest

(FIX) Secret words (added 18.08.16):
Use one of these words as a player name in the Quest mode.
URAMEN-Secret quest mode Castle 26.
HODRACH-Ending.
Source: tcrf.net

Castlevania II - Belmont's Revenge (USA), Dracula Densetsu II (Japan)

(FIX) Secret passwords (added 19.08.16):
There are three secret passwords in this game: for Last Boss battle, for Sound test and for Extra lives. The rest are provided by the game when selecting the password option on the continue screen, including two parts of the Dracula's castle. When you beat game once, the hard mode flag is raised and the second quest will be started automatically. While playing the second quest, only the hard mode password will be displayed for any stage. Note, that 0 means "Empty" slot, 1 - "Orb", 2 - "Candle" and 3 - "Heart".
0,2,3,3-No Castles Completed
1,2,3,2-Plant Castle Completed
2,3,3,1-Crystal Castle Completed
3,3,3,0-Plant, Crystal Castles Completed
0,0,0,3-Cloud Castle Beaten
1,0,0,2-Plant, Cloud Castles Completed
2,1,0,1-Crystal, Cloud Castles Completed
3,1,0,0-Plant, Crystal, Cloud Castles Completed
0,2,1,3-Rock Castle Completed
1,2,1,2-Rock, Plant Castle Completed
2,3,1,1-Rock, Crystal Castles Completed
3,3,1,0-Rock, Plant, Crystal Castles Completed
0,0,2,3-Rock, Cloud Castles Completed
1,0,2,2-Rock, Cloud, Plant Castles Completed
2,1,2,1-Rock, Cloud, Crystal Castles Completed
3,1,2,0-Dracula Castle Part One (Rock, Cloud, Crystal, Plant, Castles Completed)
3,2,1,1-Dracula Castle Part Two
0,1,0,1-Hard Mode
1,3,2,1-Last Boss
3,3,3,3-Sound Test
2,2,3,3-Extra 10 Lives
Source: gamefaqs.com

(BUR) Game genie (added 20.08.16):
00A‑30F‑C4D-Re-enables the debug cheat. During the game, on pause, press Down to restore full health bar instantly.
0B6‑15A‑C42 (for the Japanese version)
0B6‑24A‑C42 (for the US version)
-Add additional music track to the sound test, disabled in the final versions for some unknown reason.

Castlevania Legends (USA), Akumajou Dracula - Shikkoku Taru Zensoukyoku - Dark Night Prelude (Japan)

(BUR) Sound test (added 30.04.16):
An unused Sound test can be acessed by setting the RAM variables $C520 and $C521 to $0B and $00 respectively.
Source: tcrf.net

Catrap (USA), Pitman (Japan)

(GEN) Sound test (added 20.08.16):
Immediately after the console's boot up, before the title screen appears, hold Down + Left + A + B + Select. This will add an "BGM" option to the pause menu, which allows you to select the backround music.
Source: makainyumon.web.fc2.com

(FIX) Level skip (added 20.08.16):
Any time during the game, hold Start, then press Select. Release all buttons, unpause the game and just wait for a few seconds to stage being completed. If you do this cheat being in the pause mode, there is no need to unpause then.
Source: gamefaqs.com

Cave Noire

(GEN) Results tables (added 22.08.16):
At the title menu, hold Left + Start, then press B. The tables displays a maximum numbers of goals completed and enemies killed for every level in every quest.
Source: urawaza.in

Chachamaru Boukenki 3 - Abyss no Tou

(GEN) Ending (added 23.08.16):
At the title screen, press B, Select, Up, Up, Select, Down, Down, A.
Source: makainyumon.web.fc2.com

(FIX) Ingame cheat sequences (added 23.08.16):
During the game, press Select to open the floor number information window, then enter one of these codes. All codes may be combined and can be used multiple times.
Up, Down, Start, Right, Start, Right, Left, A-Monster viewer.
Up, Start, Right, Down, Left, Start, Down, A-Sound test.
Up, Down, Left, Right, Start, Right, Down, A-Max level, 34000 exp.
Up, Right, Right, Left, Start, Start, Left, A-Super quipment.
Up, Left, Down, Start, Left, Start, Right, A-Unlimited food.
Source: makainyumon.web.fc2.com

(BUR) Game genie (added 23.08.16):
3D4‑DAE‑F73-Replaces the ingame cheat for Unlimited food with the Free walk mode toggle. Enter corresponding cheat once to enable it, then one more time to disable.

Chachamaru Panic

(FIX) Cheat sequences (added 22.08.16):
All sequences should be entered at the title screen, to activate, press Start.
Down, Up, Left, A, B, Select-Round select.
Select, Select, Select, Select, Select-Play Bonus game, then exit to the title screen.
A, A, A, A, A, B, B, B, B, B, Up, Up, Up, Up, Up-Extra 9 lives.
A, B, A, B, A, B, A, B, A, B-Speed-up at the beginning.
Source: makainyumon.web.fc2.com

Chalvo 55 - Super Puzzle Action

(UNI) Sound test (added 23.08.16):
Start a new game, at the last scene of the intro with mechanic and its robot, press Up, Up, Right, Right, Down, Down, Left, Left.

(GEN) Secret passwords (added 23.08.16):
SPCLST-Start a Special Stage 9 with 50 lives.
JSSJSS-Start with 50 lives
Source: gamefaqs.com

Championship Pool

(GEN) Secret warp (added 24.08.16):
To skip the Regional Qualify and warp directly to the World Chapmionship, score 140 or lower seconds at the first round of the Speed Pool Challenge game, then start the Tournament. This cheat is unlockable and will be given to you when you complete the Regional Qualify.
Source: gamefaqs.com

(BUR) GameGenie (added 24.08.16):
C81‑27C‑E68+6C1‑2CC‑5D3-Access to unused or maybe unfinished "cheat" menu. Only the resources for the display are present, there is no code to call it properly and do anything.

Chessmaster, The (USA, Japan), New Chessmaster, The (USA, Europe, Japan Rereleases)

(BUR) Hidden text (added 28.08.16):
There is an unused copyright scring at 0x008000 in all versions of the game's ROMs:
(c)1985Kittinger
Also, the US version of the New Chessmaster has an additional credits at the end of the ROM:
PROGRAMMED
BY CRAIG B.
SEASTROM
LAST MOD.
10/11/90
for Ver 1.0, and
PROGRAMMED
BY CRAIG B.
SEASTROM
LAST MOD.
07/24/91
for Ver 1.1.
Source: tcrf.net

Chibi Maruko-chan 2 - Deluxe Maruko World

(UNI) Secret passwords (added 29.08.16):
らんらんらららん-Sound test.

Chibi Maruko-chan 3 - Mezase! Game Taishou no Maki

(GEN) Sound test (added 30.08.16):
At the title screen, open the Mini-games selection menu (third option), then just press Start.
Source: urawaza.in

Chiki Chiki Machine Mou Race

(UNI) Stage select (added 30.08.16):
Hold Down + Right before the stage and position info screen appears either after starting a new game or selecting the continue option, a Stage select screen will appears instead.

(UNI) Easter egg (added 30.08.16):
Start a new game, at the car selection screen press Up, Up, Down, Down, Left, Right, Left, Right, B, A to make all cars spinning instead of standing still.

Chikyuu Kaihou Gun ZAS

(GEN) Extra 6 continues (added 31.08.16):
At the title screen, hold A + B, then press Select 60 times. A sound will confirm code triggering. From now you'll have 6 continues instead of 3.
Source: makainyumon.web.fc2.com

(UNI) Easter egg (added 31.08.16):
Press Left/Right during the staff roll sequense after beating the game to change the rotation direction of the background stars.

Choplifter III

(UNI) Secret passwords (added 01.09.16):
When one of these passwords is accepted, the game returns to the game selection menu. Now you can either start a new game or enter the password screen again and input any regular password. You can input another secret password as well, but effects aren't combined, however it's permanent.
ZZZZZZB-Extra 6 lives.
RTDFKLN-Extra 8 lives.
LTSFBMB-Unlimited instant Rescue rope ("R") item.

Chou Mashin Eiyuu Den Wataru: Mazekko Monster 2

(UNI) Cheat sequenses (added 23.11.16):
All these cheat sequenses should be entered right after the main game title being positioned in the middle of the screen during the starting the title screen animation, but before the "PUSH START" message appears. You'll hear a sound for every 3-button nibble. Also note, that you can enable this cheat if there is a valid save data present in the battery backed RAM, so first you should play this game and save it at least once.
A, Select, Select-Unlock all food and items information in your pocket library.
A, Select, Select, A, Select, Select-Previous effect and additional unlock all field locations.
A, Select, Select, A, Select, Select, A, Select, Select-Both previous effects and additionally unlock all monsters information and raise flag for both endings.

(UNI) Secret words (added 23.11.16):
Enter one of the following words as a player name.
ひろいおうじ-Start a new game with 8th storage bottle filled with "タマプー" creatures.
みえるんです-During the game in the field mode (where the creatures are living), press Select to see statistics on all creatures on current field. Also, you can reset the console and return back to the title screen, then press Select to enter the Creatures Viewer, allowing you to see all the creatures and all its animations.
A・ユニット-Start a new game with 8th storage bottle filled with "ドラカイザー", "ドランドー", "ユノドーラ", "ドラビューン" and "パルドラピ" creatures, 2 of a kind.
みやび-Start with all 16 items, 10 of a kind.

(BUR) Game genie (added 22.11.16):
130‑9EB‑E62-Enter the Routine Test mode after the Banpresto Logo. Use the D-Pad buttons to select any of the game main handlers and run it with Start.

Chousoku Spinner (Yo for It)

(BUR) Hidden text (added 27.02.18):
The Cart RAM initialization routine uses two following strings as a signatures for data:
CHOUSOKUSPINNER
and
YO_FOR_ITVer0.5


Chuck Rock

(BUR) Hidden text (added 01.09.16):
There is a hidden copyright string at 0x000150 in the ROM:
COPYRIGHT SPIDERSOFT 1992


Cliffhanger

(BUR) Hidden text (added 01.09.16):
There is a hidden copyright string at 0x000150 in the ROM:
COPYRIGHT SPIDERSOFT 1993


Collection Pocket

(UNI) Shot-em-up stage skip (added 02.09.16):
Start to play any shot-em-up style game, when message "STAGE XX" is appear on the screen, hold A + Select and wait until it changes to "STAGE XX CLEAR".

(BUR) Hidden text (added 02.09.16):
The random number generator in this game initializing with an ASCII string: "STAR".

College Slam

(UNI) Secret teams (added 03.09.16):
Both cheats should be entered at the title screen. A sound will confirm correct code entry. Each cheat will disable another one when triggered, so you can have only one enabled at once.
Hold B, wait for 5 seconds, then press A-Two extra teams: Acclaim (White Team) and Torus (Cavemen).
Hold A, wait for 5 seconds, then press B-Seven extra Fraternity teams.

(UNI) Max team points (added 03.09.16):
At the main menu, enter "GAME OPTIONS", then "EDIT TEAM". Select any team, then at the "EDIT STATS" screen put cursor to the "Exit" option and press B, A, Down, Right, A, Down, Up, A, Down. This will temporarily set MAX points for all members of currently selected team to 60. When you re-enter this screen once again all MAX values will be restored, but all points assigned to any team member previously will be saved.

(UNI) Tonight's match-up screen cheats (added 03.09.16):
All these cheats can be entered at the Tonight's Match-up screen in any regular game mode except "PRACTICE" (which is haven't it). All of them affects only the current match and used for adjusting game-play mechanics (similar to all other ports of this game to many platforms). You can input only one cheat at once and have no retries, so if you make a mistake, you can try again only the next round. Upon entering the sequence, press Start to accept it and begin a game. A sound will confirm correct code entry. Additionally, at the beginning of the round a small message will appear at the bottom of the screen with a short name of used cheat (except two, see below).
Down, B, Up, Up, Down-Shot percentage display at the bottom of the screen. The only correct cheat for this game from the gamefaqs.com. The rest are just trash.
A, Right, Left, Left, Left, Left-Quick hand
B, Right, Right, Right, Left, Right, B-Max power
Down, Up, Right, Up, Down, Right-Goaltend
A, Left, Down, Right, Right, B-Always on Fire
Up, Left, B, B, B, A, Down, Down-Turbo
Up, Down, A, B, Up, A, B-Offence
Down, Up, Up, Down, Left, Right, Left-Always do 3-pts shots
B, A, Left, Right, A, B-Ultra jam
Right, Down, Down, Right, A, B, A-Unknown (displays only "Push")
A, A, Up, Up, Up, Up, Left, Left, Left, Left-Unknown (displays only "Push")
A, B, Up, Up, Up, Up, Left, Left, Left, Left-Unknown (displays only "Push")
Right, Right, A, A, A, A, A, Right, Right, Right-Unknown (displays nothing)
A, Down, Up, Down, Up, Down, Right, Up, A, A, A-Unknown (displays nothing)
Right, A, Down, B, A, Left, Left-Show time

Contra (Japan), Operation C (USA), Probotector (Europe)

(FIX) Cheat sequenses (added 24.11.16):
All cheat sequenses should be entered at the title screen, when title animation is over.
Up, Down, Left, Right, Start-Sound test (all versions)
Up, Up, Down, Down, Left, Right, Left, Right, B, A, B, A, Start-Stage select (the US and the European versions), Extra 9 lives (the Japanese version, the Stage select is enabled here by default)
Up, Up, Up, Up, Down, Down, Down, Down, Left, Left, Left, Left, Start-Extra 9 lives (the US and the European versions only)
Source: gamefaqs.com

(BUR) Game genie (added 24.11.16):
00A‑EBF‑C4D-Re-enables the simple sprite viewer. Just press Start during the game and press A/B to cycle through all possible ingame sprites at the player's position.

Contra - The Alien Wars (USA), Contra Spirits (Japan), Probotector 2 (Europe)

(FIX) Secret passwords (added 24.11.16):
When enter one of the secret password you'll hear a special sound and return back to the Konami logo automatically. The effects can be combined, just enther the "PASSWORD" option again and input another password.
B32R-Infinite lives.
Source: gamefaqs.com
P3LS-At the title screen, start a new game to see an Ending.
H2F2-Press Start during the game to complete current level instantly.
Source: gamefaqs.com
M1LZ-Allows you to play past Level 3 on Easy mode.
K4RN-Reverse the D-Pad buttons during the game.

(BUR) Invulnerability (added 25.11.16):
The secret passwords in this game uses RAM variable $C1E4 to store its flags. Bits 0-4 of this variable corresponds to the secret passwords in the same order as in the table above. But the game uses additional bit 5 as invulnerability flag, which is can't be set during the game and seems just a leftover from the developement stage or were planned to be enabled with additional sixth secret password as well. You can set it manually using the cheat codes, just write $20 to $C1E4. Note, the only enemy able to damage you is the flying enemies in Level 3 which grabs you and fly out of the screen.

Cool Spot

(GEN) Stage select (added 28.11.16):
At the title screen, press Right, Right, Right, Left, Left, Left, Right, Left. During the game, press Start then hold Select and press Start again.
Source: gamefaqs.com

Cool World

(UNI) Cheat mode (added 28.11.16):
At the title screen, hold Up, then press A + B 8 times. A sound will confirm cheat triggering. Input this code one more time to switch this cheat off. When enabled, at the title screen, hold Down + A and press B to select the starting level. Also this code grants you the infinite lives during the game.

Cosmo Tank

(FIX) Sound test (added 11.11.16):
During the quest mode game, press Start to pause it, then hold Down + A + B and press Start again.
Source: urawaza.in

Crayon Shin-chan - Ora to Shiro wa Otomodachi Da yo

(BUR) Game genie (added 28.11.16):
6C1‑54E‑A2B+111‑55E‑E6E-Any time during the game, use the regular soft-reset code (A + B + Select + Start) to enter the debug menu. You can select the starting level, enabe the invulnerability, increase the lives counter up to 63, as well as listen to the game music and the sounds. The "てき" flag never used in game, so does nothing. Exit this menu to the title screen and begin a new game to apply changes.

Crayon Shin-chan 2 - Ora to Wanpaku Gokko Dazo

(BUR) Game genie (added 30.11.16):
A8E‑90F‑A2B+0EE‑90F‑E6E-Any time during the game, use the regular soft-reset code (A + B + Select + Start) to enter the debug menu mostly exactly the same as in Part 1. You can select the starting level, enabe the invulnerability, increase the lives counter up to 63, as well as listen to the game music and the sounds. Instead of unused "てき" flag, here is "サブ" can be enabled and havily used during the game (investigate).

Crayon Shin-chan 3 - Ora no Gokigen Athletic

(GEN) Extra mini-game (added 03.11.16):
At the title screen, press Up, B, Right, B, Down, B, Left, B. A sound confirm correct code input. This will add an extra 10th mini-game "ACTIONMASK VS SHINCHAN" to the mini-games menu. Normally this mini-game can be unlocked after the final credits if all 9 mini-games are beaten.
Source: urawaza.in

Crayon Shin-chan 4 - Ora no Itazura Daihenshin, Super Mario 4 (Pirate)

(UNI) Secret passwords (added 14.12.16):
かみしばい-Test mode screen. Allows you to see all conversations, level intros, both endings and play minigames between stages.

(BUR) Game genie (added 14.12.16):
003‑57B‑F7A-At the title screen, start a new game to enter the Debug menu instead. Allows you to play any level from the beginning or from the midpoint, select amount of lives, items to carry, as well as to enable invulnerability. Also you can listen to all music and game sounds. Note, there are no numbers displayed because of lack of the proper font in the title screen CHR data, however they are selectable by pressing Left/Right anyway.

Crystal Quest

(UNI) Secret options (added 21.12.16):
There a few secret options that can be accessed via the secret button codes listed in the table below. All must be entered at the title screen. You could have only one option at a time before the game. But enabled options are kept permanently even after the game over.
Up, Up, Up, Down, Down, Down, Left, Right-Starting Wave select (up to 40).
Left, Right, Left, Right, Up, Down-Shot mode select.
Down, Down, Down, Up, Up, Up, Left, Right-Ship speed select.

(UNI) Continue (added 21.12.16):
When the game over message is displayed, press Down + Select + Start.

Cutthroat Island

(BUR) Game genie (added 12.01.17):
511‑9BF‑196-Replaces the title screen with the Demo Mode screen, where you can select any level to play and enable some debugging display during the game.
Source: tcrf.net

Cyraid (USA), Bakuretsu Senshi Warrior (Japan)

(GEN) Suicide:
Any time during the game, except the bonus stages, hold B, then press Select.

(GEN) Secret passwords:
Enter one of the following words as a password.
THEEND-Harder mode (unlockable after beating the game once).
MUTEKI-Invulnerability.
EPOSAS-Level skip. Hold A and press Select during the game.
Source: gamefaqs.com

DX Bakenou Z

(UNI) Secret message (added 01.03.17):
Hold Start + A + B + Right, then power the console on. In the main menu, enter 5th option ("SYSTEM"), then 4th ("SOUND TEST"). The developers logo will appear at the top-left corner of the screen.

(UNI) Credits (added 01.03.17):
Hold Start + A + B + Left, then power the console on. The screen will turn white for about 2 seconds, quickly release all buttons and press Select within this time. If done right, the Credits roll will be displayed.

(BUR) Hidden text (added 01.03.17):
The SRAM initialization routine in this game uses as a signature string:
lovelymilk


Daedalian Opus (USA), Bouken! Puzzle Road (Japan)

All versions:

(GEN) Secret passwords (added 17.01.17):
ZEAL-Stage select
Source: gamefaqs.com

US version:

(BUR) Game genie (added 17.01.17):
621‑5FF‑3B3+081‑60F‑2A2-With this code, at the title screen, enter the PASSWORD option to see some kind of very simple drawing mode instead. The background is filled with a brick wall tiles by default. Hold A, then use the D-Pad buttons to draw with black tile, hold B and also use the D-Pad buttons to erase black tiles. There is no such code in the Japanese version at all.

Daffy Duck - The Marvin Missions

(GEN) Super stage (added 17.01.17):
Step on the cart right at the beginning of the first level. This makes Daffy acquire a lot of speed as long as he doesn't touch the ground. If you manage to reach the end of the room at high speed, instead of loading the next room, the game will show a black screen with the text "Super stage" and you can play through a new set of levels.
Source: gamefaqs.com

(FIX) Pause cheats (added 17.01.17):
Pause the game, then enter one of the following button sequences to get the corresponding effect. Note, every cheat costs you 10 points, which is given during the game for defeating enemies. However, the jetpack refill cheat will only work if you have at least 20 points. To restore to the default weapon and reset all cheat counters, also on pause, press Select.
Code|Effect|At bosses?|Mode
Up, Up|Laser weapon|No|Any
Left, Left|Bounce weapon|No|Any
Right, Right|Autofire weapon.|No|Any
Down, Down|Wall break weapon.|No|Any
B, B|Refill health bar.|Yes|Any
A, A|Refill jetpack.|Yes|Super stage only
Source: gamefaqs.com

(FIX) Secret passwords (added 17.01.17):
This is not quite a secret passwords list. The passwords system in this game is very lame. Although the game gives always the same passwords, you can use any other numbers with just one condition: the sum of the numbers in password should match the particular stage requirement. The complete list of sums you can see in the table below. For example, the stage 3 sum is 11, the default password is 04070 (4+7=11), but you can use any of these: 13070, 12161, 90002, etc...
Sum = 20-Stage 1
Sum = 17-Stage 2
Sum = 11-Stage 3
Sum = 22-Stage 4
Source: gamefaqs.com

Daiku no Gen-san - Robot Teikoku no Yabou

(UNI) Cheat mode (added 22.04.17):
To enable the cheat mode, at the title screen, press Up, A, Down, B, Left, Right, Left, Right, B, A. A sound will confirm correct code entry. There are several options available now.
At the title screen, press and hold Start. While holding it, wait for the "PUSH START" message stops to fade in and out, then press B button a number of times corresponding to the Stage or substage number including bosses, up to 13. Every time you press the B you'll hear a sound. Release, Start to begin the game from the selected Stage.
During the game, press and hold Start. While holding it, wait for the pause jingle is over, then enter one of the sequences from the table below to get the corresponding effect. Every time you press the correct button, you'll hear the same sound effect as on the title screen when cheat is activated.
Also, you can use now Select to freeze the game as an alternative to the pause mode.
Right, Left, Right, Left, Down, Down, Up, Up, A, B-Refill lives.
Up, Down, Up, Down-Instant Game over.

(BUR) Hidden text (added 22.04.17):
There is a version string at the beginning of the sound engine in the very first bank of the ROM:
** Ver 6.04 **


Darkwing Duck

(BUR) Game genie (added 19.01.17):
C88‑B68‑F79-Re-enables the Stage select screen. To access it, just press Start at the title screen. The Stage select screen meant to be accessed via button sequence code Up, Down, Right, Left, A, B, Select at the title screen. The sequence check routine still present in the ROM at 07:78D1, but there are no script commands to call it, as well as there are no references to the unused portion of the title screen script, which selects the Stage select mode.

Days of Thunder

(BUR) Game genie (added 20.01.17):
00A‑04F‑E6E-Start a new game and select any game mode to get to players number selection screen, which is presumable should be started before the main menu selection. The code doesn't allow you to play the 1-player mode from there, but you still can run rather unfinished 2-player mode if use the link cable with two Game Boys. There are a lot of issues with this mode, some wrong positioned texts on the screen, you can't change the car color or player name. You able to select the course and play it somehow, but it mostly playable. The 4-player mode need some device, but even if you have it, you can't play this mode. It's quite in a basic state and working only as the 4-player hardware checking and players ready status display. The rest of the code doesn't connected even to this code at all, and has no any texts or screen layouts.

Dead Heat Scramble

(GEN) Stage select (added 21.01.17):
At the title screen, put cursor to the "1 PLAYER" option, press B 8 times, then A 8 times. Now, press B to cycle between levels 1 to 10. Press Start to begin a new game from the selected level.
Source: gamefaqs.com

Dennis the Menace (USA), Dennis (Europe)

(BUR) Hidden text (added 23.01.17):
There is a hidden version string in the ROMs of both regional versions at $0063 offset:
Version 1.0Time 12:46:27Date 09.20.93
for the US version, and
Version 1.0Time 12:47:19Date 09.20.93
for the European version.
Source: tcrf.net

(BUR) Game genie (added 23.01.17):
011‑58F‑E6A-Re-enables the Stage select screen right before the game starts.
Source: tcrf.net

Desert Strike - Return to the Gulf

(GEN) Secret passwords (added 23.01.17):
BQQBZH-A message "HELLO, LITTLE OLD LADY" will appear. This will give an extra 10 lives instead of 3 at the game start.
Source: tcrf.net

(BUR) Hidden text (added 23.01.17):
There is an unused string at $45A5 in ROM:
GO FOR SOUND
which is most probably the only leftover from planned or removed Sound test mode.

Dexterity (USA), Funny Field (Japan)

(UNI) Stage select (added 24.01.17):
Start a new game, select the game type and BGM music, before pressing Start, hold one of the following combinations to start from the corresponding stage.
Up + Left + B-Round 11 (Single mode), Round 1 (Multi mode)
Up + Right + B-Round 21 (Single mode), Round 2 (Multi mode)
Down + Right + B-Round 29 (Single mode), Round 3 (Multi mode)

Dick Tracy

(GEN) Secret passwords (added 24.01.17):
47214-Enables the Debug mode. There is no any indication when you enter this pass correctly. But now, during the game:
Press Up + Select + Start to toggle invulnerability.
Press A + Select + Start to skip to the next stage.
Press B + Select + Start to deduce one continue without any indication as well.
Also you can see the player's coordinates at the bottom-left corner of the pause screen.
Source: tcrf.net

Dino Breeder, Jurassic Park 3 (Pirate)

(GEN) Easter egg (added 11.05.18):
At the save file selection menu before the game, enter the "てきキャラずかん" ("Enemy picture book") option. Scroll pages while holding Select to change all enemy regular pictures to those as if they get hit.
Source: urawaza.in

Dino Breeder 2

(BUR) Game genie (added 26.01.17):
FA2‑AAF‑E65-Re-enables the Stage select at the beginning of the game. Hold Select before the main game field appears either after the creating the new game or continuing the saved one.
The screen will stay white and will wait for some input.
Press B to cycle between 20 available starting stages, press Left + B to set the maximum stage number.
Press Start to begin the game.
Any time you press a buttou you'll hear a corresponding sound.
FA3‑BCE‑E65-During the game, press Up + Left + Select to grow the Dino up to the next level.
FA1‑ABD‑E65-Pause the game with Start, then press Select. The effect is exactly the same as for the previous code.
FA2‑DFB‑E65-At the save game selection screen, hold B + Select and enter the Enemies library to open all records.
FA6‑349‑E65-The same as previous with the same button code, but for the New creatures library.
FA6‑F09‑E65-Additionally for the New creatures library select any entry, press Up + Select or Down + Select to fill or erase corresponding creature record.

Disney's Mulan

(BUR) Game genie (added 27.01.17):
041‑F2B‑E66+042‑00B‑E66-Allows to select an extra 4th option in the Options menu, which happens to be glitched and seems unfinished Sound test mode.Press Left/Right to select the sound effects, there is no music selection in this code.
Press B to play it.
Effects can't be stopped, which may cause the problems and more glitches. There is no text for menu option, but the ROM contains a table with set of text resources for displaying numbers from 0 to 39, which is a number of possible selectable sound effects in working code.

Dodge Boy

(UNI) Secret passwords (added 28.01.17):
NIKNO-Ending.
MAKYU-A special match. Your team is Australia and you already beat the China, now is the match against USA. This cheat uses the regular pass "ET9RG" for setup the game, but raises the special flag, which meaning isn't checked carefully, but seems it enables all power throws during the match.

Donkey Kong

(GEN) Data all clear (added 01.02.17):
At the Select File screen, press B + Select + Start + Left to enable the "DATA ALL CLEAR" menu which allows you to erase all saved files at once.

Donkey Kong Land (USA), Super Donkey Kong GB (Japan)

(BUR) Hidden text (added 01.02.17):
There are a lot of unused hidden copyright sctings spreaded through the ROM:
* By Paul Machacek / RARE LTD *
and
*By  Paul Machacek*
in both regional versions, and
PAULMACHACEK
only in the US version.
Source: tcrf.net

Donkey Kong Land 2 (USA), Donkey Kong Land (Japan)

All versions:

(FIX) Stage quit (added 02.02.17):
To exit from already completed stages any time, pause the game then press Select.
Source: gamefaqs.com

US version:

(GEN) Save screen cheats (added 02.02.17):
At the Save game selection screen, hold Left or Right, then enter one of the following button sequences. The codes may be combined. A sound will confirm correct code entry. Although the Japanese version has this cheat disabled, the code and flags are still working there. While at the Save game selection screen, set the lower three bits of RAM variable $FFF9 to raise corresponding flags, then start a game.
A, A, B, B-Extra 50 lives
B, B, A, A-Extra 40 Banana Coins
A, B, A, B-Extra 47 Kremkoins
Source: gamefaqs.com

Donkey Kong Land III

(GEN) Title screen cheats (added 03.02.17):
All cheats are for the title screen. Enter one of the sequences from the table below, then press Right to finish the code input, a sound will confirm correct code entry. Codes can be combined.
Up, Up, Down, Left-Matching Card Game
Down, Down, Up, Left-Extra 50 Lives
Up, Down, Left, Left, Down, Up-Unlock all levels
Source: gamefaqs.com

Doraemon - Taiketsu Himitsu Dougu!!

(FIX) Secret passwords (added 03.02.17):
むてき-Invulnerability. However, you still can die at some obstacles, like pits.
Source: imasaragame.com
へいき-Weapon select. Press Select any time during the game. Note, in the overworld mode the same button shows the map as well, so you need to press Select twice in row.
さかた-Weapon select and Stage skip. To skip the stage, pause the game then press Select for the overworld stages or A for other game events.
ももこ-Invulnerability, Weapon select and Stage select. Additionally all cutscene messages are skipped automatically. You only be able to press A to exit from the cutscene mode.
Source: imasaragame.com

Doraemon 2 - Animal Planet Densetsu

(GEN) Sound test (added 04.02.17):
One of the items that hidden in the River stage of the game called "MINI KARAOKE SET" and when used start a Sound test mode.
Thanks Yamada_Arthur for info.
Source: imasaragame.com

(GEN) Secret passwords (added 04.02.17):
むてきになります-Invulnerability. Note, the game need 10 letters in password, so you must fill last two positions with any letters. A sound will confirm correct code entry.
Source: makainyumon.web.fc2.com

Doraemon Kart

(GEN) Cart RAM clear (added 06.02.17):
Hold A + B + Down, then power on the console. A sound will confirm correct code entry. Your current saved game will be earased.

(FIX) Unlockables (added 06.02.17):
Complete the Story mode once with any character-Unlock Extra sixth character Dorami-chan as well as Extra three Momoko's courses.
Complete the Story mode twice with any character-Unlock a Free course mode. Now all character's courses of all levels are available to play at once and you may select any character before playing any course. This also unlocks an Extra Doraemon-shaped course.
Source: gamefaqs.com

(GEN) Ending cheats (added 06.02.17):
Unlock Free course mode as described above. Now, complete all the courses including the Momoko's courses and the Doraemon-shaped course (19 in total). If done right, there are two cheats will be enabled at the title screen. Hold one of the following combinations to get the corresponding effect.
Down + Left + B-See Ending 1
Up + Left + B-See Ending 2
Source: urawaza.in

Doraemon no Study Boy 5 - Shou 2 Sansuu Keisan

(UNI) Debug leftovers (added 07.02.17):
There is a debugging feature left in the release version of this education program. To enable it, hold A or B or both, then power the console on. This feature should work mostly as auto solver for exercises upon pressing A. However, it seems they just forgot to remove it at some point of developement, then made some changes incompatible with the old debugging code. As a result, when used in the release version, it causes a lot of problems like garbled graphics and even hanging the console.

Double Dragon

(BUR) Game genie (added 08.02.17):
043‑76F‑E6A-Re-enables simple Stage skip feature. During the game press Select to instantly complete current stage.

Double Dragon II (USA), Nekketsu Kouha Kunio-kun - Bangai Rantou Hen (Japan)

(BUR) Game genie (added 08.02.17):
00A‑92F‑E66 (for the US version only)-The US version of this game has two intro cutscene frames with blood and killing, obviously removed due to censorship. Both still sitting in ROM and can be accessed with this code.
Source: tcrf.net
30B‑769‑E6A (for the US version)
30A‑509‑E6A (for the Japanese version)
-Re-enables additional finishing move after foot-kick from the close range (the B button). In the release version there is no difference wether you hold Left or Right during the kick or not. This code adding the difference to kicks with Left/Right held. It will do grip and throwing move instead of high jump with kick.

Double Yakuman

(GEN) Credits (added 10.02.17):
At the title screen, hold either Left or Right, then press B.
Source: urawaza.in

(UNI) Tile fetch editor (added 11.02.17):
At the title screen, enter the Credits screen as described in section above exactly 3 times, then start a "1-PLAYER" game. During the game, before the tile is fetched, press Start to enter the Tile fetch editor. There are 16 numbers will be displayed on the screen. Use D-Pad button to select any of them, and A/B button to increase/decrease them. The numbers represents the custom tiles queue, which will be used first to select the next tile. Note, you can't see the other player's hand, so you may choose tiles already fetched, they won't be tossed to you obviously, the regular tile fetching procedure will be used instead. To be able to use the same cheat in "SIMPLE MODE", you must enter the Credits screen 254 times instead.

(UNI) Tile fetch cheat for 2-players mode (added 11.02.17):
At the title screen, enter the Credits screen as described in section above exactly 255 times, then start a "2-PLAYERS" game. It somehow will adjust the tile fetching as well, but need to investigate what exactly it does.

(UNI) Secret pictures (added 10.02.17):
Play the "MAHJONG HOUSE" mode of the "1-PLAYER" game. Select either Maririn or Inajima Oryuu as opponent. Finish match with positive points. At the match results screen enter Up, Down, Left, Right, B. The default message of the opponent will change and the face animation of the character will stop. Now, press any button to advance to the secret pictures of particular girl.

(BUR) Special secret picture (added 10.02.17):
There is one more much complicated cheat sequence exists in this game (Up, Down, Left, Right, Up, Up + A, Down, Down + A, Left, Left + A, Right, Right + A, B, A + B, Right, Right + A, Right + A + Select, Left, Left + A, Left + A + Select, Down, Down + A, Down + A + Select, Up, Up + A, Up + A + Select, B, A + B, A + B + Select). It should be entered at the Inajima Oryuu's secret picture. If done right, the breasts area of the girl will be replaced with some patch, but the patch data exactly the same as used in the original picture, so nothing is changes. Most probably, they planned to add some nudity or the original pictire were different, but currently there is no point to use this code at all. The only indication that this sequence is working, that the face animation of the girl will stop as well.

(BUR) Game genie (added 10.02.17):
FEF‑FFC‑E6A-Re-enables the Debug features. Most noticeable ones are:
The opponents tiles are now can be seen during the game.
The Tile fetch editor overwriting with more powerful memory viewer/editor. The corersponding cheat at the title screen also disabled, memory view now availableany time by pressing Start.
The tile fetching procedure becomes trivial. The game will just select the tiles in its order in a stack.
Adds a new shortcut for "2-PLAYERS" cheat, described above. Instead of entering the Credits screen 255 times, you just need to enter it 4 times at the title screen, then start the "2-PLAYERS" mode.
000‑00B‑C4D-Additionally to the code above, this one adds some debugging display during the game match at the top-right corned of the screen, under the opponent's tiles. There is not clear what it means, but holding Up, then pressing Left or Right during the game sometimes will reveal some changing values there.

Double Yakuman II

(GEN) Credits (added 10.02.17):
At the title screen, hold either Left or Right, then press B.
Source: urawaza.in

(GEN) Alt game field type (added 10.02.17):
At the title screen, hold either Left or Right, then press A or Start to begin the game. This will start the game with a different field type. Also, you can switch between two different field types during the game if hold Up, then press Start.

(UNI) Tile fetch editor (added 11.02.17):
At the title screen, enter the Credits screen as described in section above exactly 11 times, then choose the "OPTION START" mode. During the game, before the tile is fetched, hold Down, then press Start to enter the Tile fetch editor, exactly the same as in the first part of this game (see above). To be able to use the same cheat in "QUICK START" mode, you must enter the Credits screen 254 times instead.

(UNI) Tile fetch cheat for 2-players mode (added 11.02.17):
At the title screen, enter the Credits screen as described in section above exactly 255 times, then start a "2-PLAYERS" game. It somehow will adjust the tile fetching as well, but need to investigate what exactly it does.

(BUR) Game genie (added 10.02.17):
FEF‑FFC‑E6A-Re-enables the Debug features. Most noticeable ones are:
The opponents tiles are now can be seen during the game if the side-by-side field type is selected.
The Tile fetch editor overwriting with more powerful memory viewer/editor. The corersponding cheat at the title screen also disabled, memory view now available any time if you hold Down, then press Start.
The tile fetching procedure becomes trivial. The game will just select the tiles in its order in a stack.
Adds a new shortcut for "2-PLAYERS" cheat, described above. Instead of entering the Credits screen 255 times, you just need to enter it 4 times at the title screen, then start the "2-PLAYERS" mode.

Double Yakuman Jr.

(BUR) Game genie (added 10.02.17):
FEF‑FFC‑E6A-Re-enables the Debug features, exactly the same as in the non-junior version, but with the exception that the Tile fetch editor disabled here at all, although the code for enabling it still there.
041‑A0D‑E62-Also, the Junior version has the cheats for secret girl picture displaying removed. However, the picture and displaying code is still there exactly the same. Use this GG code, then play any match with Maririn to see its picture instead of the match results screen, or play any other opponent to see the Inajima Oryuu's picture as well.

Downtown Special - Kunio-kun no Jidaigeki dayo Zenin Shuugou!

(GEN) Secret words (added 11.09.17):
Start a new game, press Start, Start to enter the in-game menu. Open rightmost option at the bottom ("なまえ", "Name"), then enter following word as a first character's name ("くにまさ"). Note, the nigori symbol at the end must be entered separately after "し".
いいかんじ-Extra 999999 money and unlock all special moves for both players.
Source: urawaza.in

Dragon Ball Z - Gokuu Gekitouden

(FIX) Mini-games (added 16.02.17):
Right before the title screen, while the opening text is scrolling up, enter Up, Down, Left, Right, Down, Up, Right, Left, then press any button to advance to the title screen, then one more button to skip to the title menu. An additional item "MINIGAME" will appear. There are 4 mini-games available, as well as "learning" room.
Source: urawaza.in, gamefaqs.com

(FIX) Secret passwords (added 16.02.17):
The password system here is available only for the "2P BATTLE" game in the SGB mode. It is used for some character parameters generation: AP/DP/SP/CP/BE and EE. There are two types of passwords, generated ones (you can obtain one after completing the game after the staff roll, which saves your current character's parameters), and a secret ones. Here is the list of the secret passwords.
FEDCBA9876543210-AP 99/DP 99/SP 99/CP 63/BE 42/EE 15
Source: urawaza.in, gamefaqs.com
1111111111111111-AP 00/DP 00/SP 00/CP 00/BE 00/EE 00
0123456789ABCDEF-AP 30/DP 30/SP 30/CP168/BE 97/EE 00

(UNI) Extra characters in tournament (added 17.02.17):
Select either the "1P TOURNAMENT" or "2P BATTLE" game mode, chose "NEW GAME" option, setup the game, then finally press A to begin the actual game. While the screen is white, quickly hold Up + A + Start and wait for the introduction. If done right, you can choose any character from the list, not only three main characters of the game.

(UNI) Exhibition menu (added 17.02.17):
During the game, on the way to Guru's, if you take a detour and head to the Namekian Village that's in ruins, you can play a Pushing Rock minigame there. It's not really important for the completing of the game itself, but serves another purpose. Beat all 8 stages of this minigame ("ド", "ラ", "ゴ", "ン", "バ", "ー", "ル" and "Z"), return back to the game, then hold Up + A and press Start to access the ingame menu. If done right, the menu will have one extra item ("てんらんかい" or "Exhibition") giving you the access to menu where you can view all battle and conversation pictures for all characters and listen to the music and sounds.

Dragon Slayer - Nemuri no Oukan

(FIX) Secret names (added 20.02.17):
ほろぼろ-Change the main character appearance to Chicken-like bird "Horoboro".
Source: urawaza.in
あんデド-Extra 65535 of money at the beginning of the game.

(BUR) Hidden text (added 20.02.17):
The game uses string
ARGENT91
as SRAM initi signature.

Dragon Slayer I

(GEN) Phase 2 warp (added 18.02.17):
At the title screen, press Up, Down, Left, Right, A. This code is unlockable and given to you after you clear PHASE 1.
Source: gamefaqs.com

Dropzone

(FIX) Cheat sequences (added 21.02.17):
All cheats should be entered at the title screen, after "DROPZONE ADVERSARIES" has been displayed. If entered correctly, the game will start immediately, so you couldn't use more than one cheat at once.
Up, Down, Right, Right, Left, Left, Up, Down-The Cloak timer 4 times slower.
Right, Left, Left, Right, Down, Left, Up, Right-Extra 25 lives and bombs.
Down, Left, Up, Down, Up, Down, Up, Left-Start on Wave 5.
Source: gamefaqs.com
Left, Left, Right, Down, Up, Left, Right, Down-Start on Wave 10.

Duck Tales 2

(BUR) Game genie (added 27.02.17):
0F7‑6FB‑C46-Re-enables the Stage select, exactly the same as in Darkwing Duck game. Both games shares the same scripting engine as well as the same unused disabled Stage select cheat routine and scripts.

Dungeon Land

(BUR) Hidden text (added 01.03.17):
There is a hidden copyright scring inside the ROM:
(C) 1991 RANDOMHOUSE
Also, the SRAM init routine in this game uses following string as a signature:
RH-EX008


F-1 Race

(GEN) Demo speed control (added 29.03.17):
During the demo sequence, press either A or B to increase or decrease the car speed correspondingly. Note: there is no proper indication of changed speed in this case on the game's HUD.
Source: urawaza.in, gamefaqs.com

FIFA - The Road to the World Cup '98 (USA), World Cup '98 (Europe)

(FIX) Secret passwords (added 10.04.17):
All passwords are unlockable and given to you randomly after beating the Tournament mode of this game. All effects are exactly the same as in previous part (97) made by the same developers.
100PY-During the game, kicking the ball results in its crazy behaviour. It's moving without any physics, constantly changing direction.
M#NWTD-Max out player's team parameters instantly during the game (all are higher than the best team "T*HQ Tornados").
W#11*D-Slow down the ball speed for the rival team.
B11ND-No fouls for the player's team (if enabled in the Options).
Source: gamefaqs.com

FIFA International Soccer

(BUR) Hidden text (added 07.04.17):
There is the hidden version string at the beginning of the rom:
17 Dec 1994 14:17:55
Also, there is a common Probe software copyright string at the beginning of the sound engine:
(C)Probe

Source: tcrf.net

FIFA Soccer '96

(BUR) Hidden text (added 07.04.17):
There is the hidden version string at the beginning of the rom:
29 Sep 1995 19:25:56
Also, there is a common Probe software copyright string at the beginning of the sound engine:
(C)Probe

Source: tcrf.net

FIFA Soccer '97

(FIX) Secret passwords (added 10.04.17):
All passwords are unlockable and given to you randomly after beating the Tournament mode of this game.
K00KY-During the game, kicking the ball results in its crazy behaviour. It's moving without any physics, constantly changing direction.
B+T#*M-Max out player's team parameters instantly during the game (all are higher than the best team "T*HQ Tornados").
BR1CK#D-Slow down the ball speed for the rival team.
#*G+#-No fouls for the player's team (if enabled in the Options).
Source: gamefaqs.com

Faceball 2000

(FIX) Secret names (added 30.03.17):
Go to options, then change the player's name to one of the following to get a corresponding effect.
SOUNDTEST-Sound test.
PHOTOPAUSE-Disable the splash message on pause.
CONFIG_SYS-Level select and additional parameters of the player setup.
Source: tcrf.net, gamefaqs.com
SHOWENDING-Show the ending.
EXTRALIVES-Extra 5 lives at the game start.

Family Jockey 2 - Meiba no Kettou

(UNI) Extra money (added 31.03.17):
At the title screen, press Left, B, Right, Left, Left, Right, Right, B, then choose a new game to start with 100000 money.

(BUR) Debug flags (added 31.03.17):
The Extra money cheat uses variable at address $A8C1 in Cart RAM area to store its flag. But the same variable contains two more debug flags, never raised by the game, but tested at some points.
Set bit 0 of this variable to enable the debug race skip. Instead of the race you'll jump directly to the results list with all zeroes.
Set bit 1 of this variable to enable the Barcode scan skip cheat. At any "ENTER BARCODE" screen, hold Select, then press A to set predefined Barcode data ("999999999") to use it in the game without need of the Barcodes.

Famista 2

(GEN) Ball speed mini-game (added 01.04.17):
At the title screen, hold B then press Start. Adjust throwing parameters, then pitch and catch the ball, the speed will be recorded.
Source: urawaza.in, gamefaqs.com

Famista 3

(BUR) Hidden text (added 01.04.17):
There are various copyright strings used for initializing the RAM partitions in this game:
   copyright 1993 yukihiko yagi   
Used as common Cart RAM signature.
TAKA FUKAWA
Used as regular game save slots initializer.
TAKASHI FUKAWA
Used as the special team data signature.

Felix the Cat

(UNI) Weapon and stage select (added 05.04.17):
At the title screen intro animation before the "PUSH START BUTTON" message appears, press Right, A, Down, B, A, B, Down, A. A sound will confirm correct code entry. Now, during the game press Select to power up to the next weapon instantly, or on pause press A or B to select any stages, including the boss rooms.

Ferrari Grand Prix Challenge

Japanese version:

(BUR) Hidden text (added 05.04.17):
Among other unused text resources shared in both regional versions of this game, there is an odd string at the end of BANK 2 in the Japanese version:
SEARCH - NEM - NEWLAND
This string isn't present in the US version.

Fidgetts, The

All versions:

(GEN) Restart or quit stage (added 06.04.17):
Any time during the game, press Start + Up to open the Restart or quit stage menu.

(UNI) Staff roll (added 06.04.17):
At the title screen, press Select + B + Right. In the Japanese version the credits roll much shorter than in the US version.

(BUR) Game genie (added 06.04.17):
002‑CCA‑C4D (for the Japanese version)
002‑ED3‑C4D (for the US version)
-Re-enables the Extra lives cheat. At the title screen press Start + A + B + Up. A screen will flash for a short time. Now you'll have extra 10 lives at the beginning of the game.

Japanese version:

(UNI) Secret message (added 06.04.17):
At the title screen, press B + Up once, then wait until the current copyrights message loop is over. The secret greetings from programmer will appear in place of the copyrights text. Due to completely lack of the copyright messages on the title screen in the US version, there is no similar secret message as well.

Final Fantasy Legend II (USA), Sa-Ga 2 - Hihou Densetsu (Japan)

(GEN) Sound test (added 11.04.17):
At the title screen, hold Start + Select, then press B.
Source: gamefaqs.com

Final Fantasy Legend, The (USA), Makai Toushi Sa-Ga (Japan)

(GEN) Sound test (added 11.04.17):
At the title screen, hold Down + Select (for the US version) or Left + Select (for the Japanese version), and then additionally hold B, then wait for about 4-5 seconds and release all buttons. If done right, the Sound test will replace the title screen menu.
Source: gamefaqs.com, tcrf.net

Fire Dragon (Unlicensed)

(BUR) Hidden text (added 12.04.17):
There is a hidden copyrights string at the beginning of the ROM:
GOWIN FIRE DRAGON 199404
There may be more Shift-JIS encoded text near, investigate.

Fire Fighter

(FIX) Secret passwords (added 12.04.17):
00PRJ00-Level select and infinite lives. Press A + B + Select during the game to instantly complete the level.
PLQQ23J-Level 10 (game does not give password for this level)
JK22GVV-Level 11 (ending)
VXV55ZS-Level select. Press A + B + Select during the game to instantly complete the level.
Source: tcrf.net

Fish Dude (USA), Uoozu (Japan)

All versions:

(BUR) Hidden text (added 12.04.17):
There are hidden copyright string at the beginning of the ROM:
                            1990  SALIO & ANex                  

Source: tcrf.net

Japanese version:

(GEN) Secret passwords (added 12.04.17):
At the Stage number screen, select any stage greather than 1 using A. Press Start to start a password input mode. Enter one of the following words then hold Down and press Start to enable the secret feature.
STAF-Staff roll.
MSIC-Sound test.
FONT-Toggle between default small font and a larger one.
MODE-Options menu. You can select difficult, number of lives and toggle to inverted palette.
MAPS-Stage select.
XENA-Unlock levels A-C. Note, this is only enables these levels at the Stage number screen, but you still need to know a valid passwords to play them.
Source: makainyumon.web.fc2.com

US version:

(BUR) Game genie (added 12.04.17):
Due to passwords system changes in the US version, the secret passwords were disabled. But all code still sitting in the ROM unreferenced. There is no simple proper way to re-enable them, but you can try to access some of features somehow using the following Game genie codes. To enter the corresponding function, go to the password input screen and just press Start. Also as a result of hacky method of accessing you couldn't use some features, like selecting the levels or unlocking the A-C levels.
03F‑6FF‑5DF+32F‑70F‑A2A-Staff roll.
76F‑6FF‑5DF+33F‑70F‑A2A-Sound test.
9EF‑6FF‑5DF+-Toggle font. Due to hacky method of accessing, it will garbled.
C9F‑6FF‑5DF+35F‑70F‑A2A-Options menu. You actually can make use of it.
38F‑6FF‑5DF+37F‑70F‑A2A-Stage select. Due to hacky method of accessing, won't go anywhere.

Fist of the North Star (USA), Hokuto no Ken - Seizetsu Juuban Shoubu (Japan)

(GEN) Parameters display (added 13.04.17):
At the mode selection menu, press Select + A to get to the parameters display menu. There are not only the level of characters will be displayed, but its experience points and attack/defence parameters. This code is described in the game's official manual.

(UNI) Password generator (added 14.04.17):
Note, that the game's password system uses the data's checksum to perform password permutation at the generation stage, but at the decoding stage there is no check against the real checksum. It's just permuting password back using the stored value. This password generator will generate actual game passwords, unless you use the "Checksum hack" option, where you can use your own checksum value to encode the password. Most of internet passwords for this game exploiting this feature somehow.
CharacterLevel
Kenshiro:
Heart:
Shin:
Jagi:
Uygur:
Souther:
Raoh:
Falco:
Han:
Hyou:
Kaioh:
Checksum hack:
Password:


Flash, The

(GEN) Credits (added 17.04.17):
Normally, the Credits can be seen when the demo loop is over. But if you press B at the title screen, you can see the Credits instantly.

(GEN) Pause (added 17.04.17):
During the game, press Select + Start.

(FIX) Passwords (added 17.04.17):
To enter the password, at the title screen, press Select. Althought the password in this game is 10 characters long, only the first 7 are checked by the program. Here is the full list of acceptable street names with not important parts in braces:
"23 DELA"(NEY)-Level 2
"DENIM B"(LVD)-Level 3
"TRACK 2"(9)-Level 4
"99 PICA"(SSO)-Level 5
"INGOT L"(ANE)-Level 6
"7TH MAR"(KET)-Level 7
"TRACK 1"(2)-Level 8
"RUE LE "(DAY)-Level 9
"TIN ALL"(EY)-Level 10
"GORBY W"(AY)-Level 11
"TRACK 6"(6)-Level 12
"FUN HOU"(SE)-Level 13

(BUR) Hidden text (added 17.04.17):
There is no password or street name display for the first one Level of this game. But actually, its name is stored in the passwords list with index 0 and even checked by the password system, but can't be accepted, since the valid stage index should be non-zero. The street name is:
143 FIFTH
Also, there is an unused cutscene message
-(MORE: PRESS A)-
intended to be used when a special code is inserted in the cutscene line. But In the final release there are no such codes in any cutscene texts.
Source: tcrf.net

Fleet Commander VS

(GEN) Cease fire (added 17.04.17):
During the game, in the main game menu, enter "がいこう" ("Diplomacy") option, then select "メッセージにゅうりょく" ("Input message") option. Enter word "コウフクシマス" ("Surrender"). Return back to the main game menu and choose "END" option to instantly end the battle, following with the "CEASE FIRE" cutscene.

(UNI) Disable fog of war (added 17.04.17):
At the title screen menu, hold Select + B + Left. The cursor will jumping constantly on the menu items. Press A exactly that moment, when the cursor is pointing on the first option "1P. GAME", this little bit tricky. Another method to trigger this cheat is to set the cursor position to "LOAD GAME" option, press Select + B + Left at the same time and immediately after it (when cursor is changing its position), additionally press A (do not release previous buttons!). If done right, the game will start, from now all enemy units will be visible on the map permanently.

Flintstones, The

(GEN) Stage select (added 17.04.17):
Enter the "OPTIONS" menu, now select the "FX TEST" option and play the sounds: 25, 01, 02, 02, 01, 04, 01, 02, 02, 01, 04, 15. Now play any sound one more time to enable the cheat. Return to the title screen, the message "CHEAT ON!" will appear at the upper-right corner of the screen. Start a new game, the level/mini game select screen will appear. You can select and play any mini-game, watch the ending sequence, other game sequences and play from any act as well. Also this cheats enables the stage skip feature for most of the stages. During the game just press Select to advance to the next stage. Note, if one converts the numbers of the sounds needed to be played to their corresponding letter (e.g. 01 = A, 02 = B, etc.), it spells out "YABBA DABBA DO", Fred's catchphrase.
Source: tcrf.net

Flintstones, The - King Rock Treasure Island

(FIX) Title screen cheats (added 18.04.17):
All cheats should be entered at the title screen. If done right, a sound will confirm correct code entry.
Down, Down, Down, Down, Up, Up, Up, Up-Invert screen colors permanently.
Select, B, A, A, B, Select, B, A-Hidden mini-game after the game start.
Source: gamefaqs.com, tcrf.net

Football International (USA, Europe), Soccer (Japan)

(UNI) Secret mode (added 18.04.17):
At the title screen, put cursor to "2 PLAYERS" menu option, then hold Up + B and press A or Start to begin the game. This will force the "WORDL CUP" mode to begin and starts from the "TEAM SELECT" screen instantly, but instead it will be called "SECRET MODE". Here you'll be able to select the starting round of the tournament by selecting a corresponding team to play against.

(UNI) Always penalty kick (added 18.04.17):
Enter the "Secret mode" cheat as described above. At the team selection screen, select your team, then choose the team you want to play against, hold Select and press A. If done right, you'll jump directly to the round results screen with obviously 0-0 score, so this will force the penalty kick mode to begin.

(UNI) Ending (added 18.04.17):
Enter the "Secret mode" cheat as described above. At the team selection screen, press Up, Up, Up, Left, Left, Select.

(BUR) Hidden text (added 18.04.17):
There is a hidden string near the end of bank 3 repeated 10 times:
PC-8001 FOREVER


Fortified Zone (USA), Ikari no Yousai (Japan)

(GEN) Players switch (added 19.04.17):
During the game, hold Up, then press Select + Start to instantly switch between players without need to go to the options menu.

(UNI) Secret message (added 19.04.17):
At the "GAME MODE SELECT" screen, enter "SOUND BOY" mode. Choose "PROGRAM PLAY" mode and set any sequence of the music tracks to play. Start to play the program either in "THROUGH" or "REPEAT" modes, no matter. There is a piglet character walking on the screen all the time the music is playing. At some point, this piglet will stop and make a bow to the player for a very short time. Press A + Start at exactly that moment. This may be tricky, but if done right the message "BU !" will appear above the piglet. Need to mention, "SOUND BOY" actually was written for another game: "Hero Shuugou!! Pinball Party". The piglet and fire heads are characters from that game.

(FIX) Secret passwords (added 19.04.17):
Note, that there are no infinite lives/ammo passwords, only large amount of it at start. Also note, the second portion of passwords has a dupes with exactly the same effects but different names. Also all these passwords causes a HUD glitch if simple players switch button (Start) is used for the very first players switch on the level. All secret cheats as well as chibi female mode were totally scrapped from the US version.
Regular passwords for all versions
Always start as male, default parameters.
CCCC (for the Japanese version) 1111 (for the US version)-Stage 1
TANK (for the Japanese version) 3375 (for the US version)-Stage 2
DRAG (for the Japanese version) 1681 (for the US version)-Stage 3
COMP (for the Japanese version) 1122 (for the US version)-Stage 4
For the Japanese version only
Extra 240 medkits/bullets, max lives/bullets, flame thrower weapon.
AAAA (Male) BBBB (Female)-Stage 1
GUN? (Male) JEEP (Female)-Stage 2
CANO (Male) BIO! (Female)-Stage 3
BOMB (Male) ROBO (Female)-Stage 4
Always start as male, chibi female mode, default parameters.
Simple players switch button code enabled: Start.
Stage skip cheat enabled: hold Down, then press Select + Start.
YURI-Stage 1
KEI!-Stage 2
AMI!-Stage 3
RIE!-Stage 4
Chibi female mode.
Extra 240 medkits/bullets, max lives/bullets, flame thrower weapon.
Simple players switch button code enabled: Start.
Stage skip cheat enabled: hold Down, then press Select + Start.
MINT or YOKO or MIA! (Male) MOMO or MAMI (Female)-Stage 1
ELI! or RISA or GAMI (Male) EMI! or JUN! (Female)-Stage 2
REI! or KAYO or RIKA (Male) MAI! or TAE! (Female)-Stage 3
SAKI or RUMI or ERI! (Male) YUU! or NAMI (Female)-Stage 4
Source: tcrf.net, gamefaqs.com

Frank Thomas Big Hurt Baseball

(UNI) Instant win (added 06.05.16):
Choose any game mode with scoring, start the game with "Play ball" option. Now, exit to the "Team Options" menu by pressing Start any time during the game and press Up, Down, Left, Right, Up, Down, Left, Right plus any other button to complete the sequence. A sound will confirm correct code entry. This will set the highest score to your team. Continue the game with "Play ball" option again to instantly win current round and skip to the next depending on the game mode you've played. Similar cheat can be found in other Baseball game from the same developers: "All-Star Baseball '99".

Frisky Tom

(BUR) Game genie (added 20.04.17):
C0C‑02C‑E6A+07C‑01C5DE6A+FAC‑00C‑C4D-Re-enables the Debug menu. Hold Select + Start once Frisky walks onto a stage, then press Up once and Down once in any order.
06D‑AAC‑F7E-Additionally to the previous codes use this one to enable the 6th unused line of the debug menu "BG PAL".
Source: tcrf.net

From TV Animation Slam Dunk - Gakeppuchi no Kesshou League

(BUR) Game genie (added 13.08.16):
620‑12F‑6EF-Re-enables the debug mode. Press B at the title screen. There are 7 options available from 1 to 7 correspondingly: Face test, Message test, Cutscenes test, Dunk Animations test, Offence/Defence test, Sound test, Game moves test. Presss A to enter any of tests, press Start to return back to the game.
Source: tcrf.net

From TV Animation Slam Dunk 2 - Zenkoku e no Tip Off

(UNI) Field warping (added 15.08.16):
Either at the intro or at the title screen, hold Up + Left, then press Start to skip to the next screen (to the title screen if you press when the intro is played or to the main menu if pressed at the title screen). During the game, any time on the main field screen (except the initial ball toss), press Up, Up, Down, Down to warp current player forward to about 1/5 of the game field, but not farther than the beginning of the 2-point zone. This works even if your currently controlled player has no ball in hands.

(UNI) Secret passwords (added 15.08.16):
WJUMP-Enables a Special game mode option at the title menu, which allows you to play any of 6 story mode stages as a single training stage. After this stage is over, you'll se only the game results, then return to the main menu. However, all intermission cutscenes will be displayed.

(BUR) Game genie (added 15.08.16):
622‑08F‑6EF-Re-enables the debug mode. Hold B and reset the console, you'll see a number representing one of the internal game handlers. Some of the game handlers are for debugging and can't be accessed during the game: 2 - SGB test screen (note, that garbage it displayed is because it uses the game's code instead of an actual graphics data), 4 - Hidden unused UFO mini-game, used in "Captain Tsubasa J", 5 - Attack/Defence test, 13 - Sound test, 15 - Animations test, 21 - Halftime test, 22 - Face expressions test. Press A to enter one of the selected handlers, press Start to return back to the game.
Source: tcrf.net

Fushigi no Dungeon - Fuurai no Shiren GB - Tsukikage Mura no Kaibutsu

(GEN) Cart RAM clear (added 21.04.17):
At the title screen, press Up, Left, Down, Up, Left, Right, Down, B, A, B, A, Select. A sound will confirm correct code entry. This should reinitialize the Cart RAM and reset all previous saves and settings. Most probably this cheat were described in the game's manual.

Game & Watch Gallery (USA, Europe), Game Boy Gallery (Japan), Game Boy Gallery 2 (Australia)

(GEN) Cart RAM clear (added 22.04.17):
At the title screen, press Up, Up, Down, Down, Left, Left, Right, Right.
Source: gamefaqs.com

Game & Watch Gallery 2 (USA), Game Boy Gallery 2 (Japan), Game Boy Gallery 3 (Australia)

(GEN) Pause frame pattern change (added 22.04.17):
During the game, when the CONTINUE/RETRY/EXIT menu is displayed, you can cycle throught a large amount of different animated patterns with the B button.
Source: urawaza.in

(GEN) Cart RAM clear (added 22.04.17):
At the title screen, press Up, Up, Down, Down, Left, Left, Right, Right. A sound will confirm correct code entry. In case there are an Interrup saved games from the previous play, this code will erase only the other games statistic, and additionally begin the title demo sequence instantly.
Source: urawaza.in

(BUR) Game genie (added 24.04.17):
201‑EEF‑B3A (for the US version)
201‑DBF‑B3A (for the Japanese version)
-Re-enables a complex set of the Debug menu which allows you to debug a lot of games parameters.
Source: tcrf.net

Game Boy Gallery (USA)

(UNI) Cheat mode (added 25.04.17):
To trigger this cheat on, for any game selected, at the game menu, put cursor to "START" option, hold Select + B + Up and press A to Start. If done right, the starting jingle will be different. From now you'll be able to manipulate the game's scores. Each game has its own unique score edition inputs and effects, all described in the table below. Note, the TOP scores are disabled in cheat mode, so you couldn't keep your "records".
Ball-Press Up to set the lowest digits of the scores to 99. So you can only "skip" to the next 100 points every time you get a point in the game.
Vermin-Press Up or Down to increase your scores to 100 or 10 points respectively.
Flagman-Press A or B to increase your scores to 1 to 10 points respectively during the Flagman show time. When there is the time to answer, the correct number will be hinted at the top-left side of the screen.
Manhole-Press B, same as in the "Ball" game.
Factory-Press Up or Down, same as in the "Vermin" game.

Game Boy Wars (Japan), Game Boy Wars Turbo (Japan, Rerelease), Game Boy Wars Turbo - Famitsu Version (Japan, Rerelease)

(GEN) Cart RAM clear (added 25.04.17):
At the main game menu, hold A + B, then press Left, Left, Right, Start.

Game de Hakken!! Tamagotchi 2

(GEN) Cart RAM clear (added 08.05.18):
During the game, open "Memory book" in Mika-chu's room. Hold Up + Select and press A. Release all buttons, game will reset with all data clear.

(GEN) Sound test (added 10.05.18):
Win any contest. During the game go to the stereo player in Mika-chu's room and press A.
Source: gamefaqs.com

(GEN) Picture book (added 10.05.18):
Win all contests (not sure how exactly). During the game go to the bookshelves with bunny in Mika-chu's room and press A.
Source: urawaza.in

(BUR) Unused cheat (added 10.05.18):
There is a chear leftover similar to "Extra status indicators" cheat in the first part of this game. There are no code associated for it, it seems it was completely removed but the control variable and main code still there. Modify RAM address $D455 to any non-zero value to enable an extra info displaying at the "STATUS" screen during the game.

Game Genie V1.17 BIOS (Unlicensed)

(FIX) Cheat sequences (added 29.09.16):
At the main GG entry screen, enter one of the following button sequences to get the corresponding effect.
Up, Down, Left, Right-Secret message 1.
B, A, Left, Right, Select-Secret message 2.
Up, Up, A, B, A, Down, Down-Secret message 3.
Right, Up, Down, Up, Left, Up, Down, Up-Secret message 4.
B, A, B, Right, Left, Down, Up-Secret message 5.
A, A, A, A, B, B, B, Start-Secret message 6.
Right, Left, Right, Left, Down, Down, Up, Up-Secret message 7.
Down, Up, Down, Down, Left, Right, Left, Start-Secret message 8.
A, B, A, B, B, A, A, Select-Secret message 9.
A, Left, Left, A, B, Right, Right, B-Toggles the large fonts upside-down flip.
B, Down, Down, A, B, Up, Up, A-Toggles the small fonts upside-down flip.
Source: tcrf.net

(GEN) Secret words (added 29.09.16):
At the main GG entry screen, input one of the following words as Code 3, then press A on the first space of Code 1. Note, that "-" means that this character is erased with B button.
DEAD------Toggle vertical screen shake.
ABACADABA-Toggle horizontal screen shake. Both codes may be combined.
F154------Toggle the main selection cursor into the fish and back into the hand.
FACE------Toggle the GG cursor into the face and back into the cross.
1984------"Explode" secret message.
BAC4------Toggle inversion of D-Pad buttons.
1CE‑---‑--Never release D-Pad buttons.
414E5-----Horizontal screen wave effect.
6EE6------Vertical screen wave effect
Source: RFredW

Game of Harmony, The

(UNI) Stage skip (added 24.04.17):
During the game, point the player's arrow straight up and press Up once, press B to point the arrow in opposite direction, then press Down. If done right, you'll hear the sound every time you press the direction button, from now, press Select to skip to the next level up to the last one.

Ganbare Goemon - Sarawareta Ebisumaru

(GEN) Sound test (added 27.04.17):
After the game over screen, at the continue menu, press Up, Up, Down, Down, Left, Right, Left, Right, B, A.
Source: gamefaqs.com

(UNI) Password generator (added 27.04.17):
There are icons instead of letters in this password system. In this password generator icons are numbered left to right in the top row as 1,2,3,4 and as 5,6,7 in the bottom row.
Stage:
Jewels:
password:


(BUR) Game genie (added 27.04.17):
2FC‑86F‑7FE-Re-enables the quite simple and partially non-functioning Debug screen. The values are uninitialized at start with this code. First two values represents the stage index and location respectively. Invisible option correspond to the sound player music index, but there are no code to start the music from there. The last visible options changes some game var, but it reinitialized when the game starting, so does not effect at all here.

Ganso!! Yancha Maru

(BUR) Game genie (added 12.05.18):
200‑DFB‑80A-Re-enables the debug cheat functionality. To use it, hold A + B + Select + Up + Right and power on the console. At the title screen, hold Left and press Start. Also, you can hold either A or B or both in addition to Left before hitting Start. Indication that the debug mode is enabled is there no "PAUSE" text on the pause screen.
For any combinations of buttons, during the game, press Select to instantly complete any level except 4-3.
If A were held, the timer is stopped.
If B were held, invulnerability enabled.

Garms - Operation Gundam

(GEN) SD Picture Book cheats (added 07.05.18):
At the Title menu, shoose "SDダイズカン" ("SD Picture Book"), then "G・アームズ グン" ("G-Arms Group"), now finally open "コマンドガンダム" ("Commander Gundam"). Wait for the message on the screen to fully appear. Now, press one of the following buttons to get the corresponding effect:
Left-Sound test
Down-Stage select
Source: tcrf.net, urawazagame.com

(BUR) Hidden text (added 07.05.18):
There is some ddevelopers copyright and build date text at the beginning of the ROM:
****************
*COMMAND GUNDAM*
*    G-ARMS    *
*  1991/02/13  *
****************

   Written by
Yoshitaka Ohsawa

Source: tcrf.net

GB Genjin Land - Viva! Chikkun Oukoku

(GEN) Ending (added 03.05.17):
Start a new game, buy a ticket and walk into the Theme park. Go to the exit way (middle-bottom), when asked to accept or cancel, press and hold A + B + Select instead. This is little bit tricky, because two of these buttons are used for either the exit from this menu or for the accept the selection. If done right, the ending sequence will start instead of the outro cutscene.
Source: urawaza.in

(GEN) CRT test screen (added 03.05.17):
Start a new game, buy a ticket and walk into the Theme park. Go to the exit way (middle-bottom), when asked to accept or cancel, select to accept the exit. Now, when the screen with Genjin on the log in the middle of the sea appears, press and hold A + B + Select and wait until the CRT test pattern appears on the screen.
Source: urawaza.in

(GEN) Title screen cheats (added 03.05.17):
At the title screen, put cursor to the second menu option ("Warming up exercises"), hold one of the button combinations from the table below, then press A or Start.
Left + Select-Sound test.
Right + Select-Play any mini-game with any level of difficulty.
Source: urawaza.in

GB Pachi-Slot Hisshouhou! Jr.

(BUR) Hidden text (added 03.05.17):
The CRAM initialization routine in this game uses as a signature the following string:
Yamazaki1hiroshi


GBKiss Mini Games

(UNI) Secret passwords (added 12.05.17):
This is a special cartridge with the GB KISS menu only (the other games with GB KISS support has it as the additional option inside the game, however, the menu code exactly the same for all games and cartridges). There are several games and additional files contains in this particular cartridge, but most of them are locked by passwords for some unknown reason. Also not known (at least by me), where they should've been publish those secret passwords and wether any of it is available in public now. So, consider all these password as a secret now, until someone told me it's not true. Following table contains the complete list of the files on this cartridge and how to unlock it. All games are separated by 6 categories, only the first one is unlocked from the beginning. To input password, at the main GB KISS menu, press B, then select "PASSWORD INPUT" option. If done right, the corresponding menu option will appear in the list. To transfer the game to the CRAM, choose any category, then press Start on selected game. Note, there are several data files tha need the main program in order to work properly, so you must put them in CRAM together. Every file takes up to 8Kb of the CRAM, from 32Kb in total, so you can't load all the files at once in CRAM.
Category|Unlock password|List of games/files|Notes
キャラバンバージョン 5ゲーム
("Caravan version 5 games")
|-|モグってナンボ ("Mogutte Nanbo")
SAMEGAME KISS
ジャカジャカジャンプでポン ("Jaka-Jaka-Jump")
がんばれマグネッシMAIN ("Drive" main file)
がんばれマグネッシDATA ("Drive" data file)
SHOOTING MASTER
|Both "Drive" files should be in CRAM at the same time in order to work properly.
キスモン&バケちゅリレーほか4
("Kissmon&Bucket Relay and 4more")
|KISSMON|KISS MONSTER
ストップウォッチ&タイムー ("Stop Watch")
かんい でんたく ("Calculator")
バイオリズム ("Biorhythm")
サウンド ルーム ("Sound test")
バケちゅリレー("Bucket Relay")
|"KISS MONSTER" is an earlier version of the same tool, included in Japanese "Pocket Bomberman" (the only available mini-game there by default).
15パズル&キャノン ほか4こ
("Puzzle 15&Cannon and 4 more")
|CANNON|アイコンデータしゅう ("Icons data")
アイコン エヂィター ("Icons editor")
15パズル&パネル ("Puzzle 15")
スロット マシン ("Slot machine")
キャノンボール ("Cannon Ball")
ポーカー ("Pocker")
|-
バイナリーランド&BJはか2こ
("Binary Land&BJ and 2 more")
|BINARY|WORM
バイナリーランド ("Binary land")
ルーレット ("Rulette")
ブラックジャック ("Black jack")
|-
ミニゲームがぞういれかえデータ
("Mini games picture replacement data")
|GAMEDATA|15パズル データ1 ("Puzzle 15" data 1)
15パスル データ2 ("Puzzle 15" data 2)
15パズル データ3 ("Puzzle 15" data 3)
モグってナンボ データ ("Mogutte nanbo" data)
スコップウォッチすうじデータ ("Stop watch" data)
|Expansion packs for the previous mini-games.
GB KISS TOOLS|KISSTOOL|SRAM GET&CLR
FILE ALL DELETE
CHAR DUMP
|Sends the CRAM or CHR data via IR port to PC or just wipe all CRAM data (keep settings and unlocked passwords).

Gear Works

(UNI) Secret passwords (added 15.05.17):
At the Code entry screen first enter "0105" as a password and press B. Start a new game, press A + B to commit suicide three times to lose all lives and return back to the title screen. Now, at the Code screen, enter password "1967" and start a new game again. From now, the A + B combination will skip current stage instead of restarting it with losing a life. Also, you'll get extra 9 lives and 99 of every items. The password numbers are clearly the someone's birth date.

Gekitou Power Modeller

(UNI) Title screen cheats (added 12.06.18):
At the Capcom logo, press Up, Up, Right, Right, Down, Down, Left, Left, a sound confirm correct code entry. This cheat is enabled permanently and cheat flag stored in Cart RAM. From now, at the title menu several extra options are available. To choose one of them, put cursor on the corresponding option, hold particular button and then press either A or Start. The option/button combinations described in table below.
Menu option|Button|Effect
"START"|Right or Left|Free battle mode. Choose any robot character, then fight with every other robots.
"CONTINUE"|Left|The same as previous, but you can choose robots available in a players roster for currently saved game.
"CONTINUE"|Right|Sound test in a play list mode. Similar to the "OPTIONS" menu Sound test but you couldn't select music tracks, only repeat currently played one with B. There is no "MESSAGE SPEED" option here. Also this Sound test starts with a Capcom logo jingle otherwise unavalilable in a regular Sound test.
"VS"|Right|Battle watch mode. Random CPU controlled robots will fight each other.
Additionally, this cheat enables a manual music control at the battle mode. Pause the Battle, then use Left/Right to choose background music, press A to play it. Press B to fade music out or press Up to stop music immediately. There are also several features available in multiplayer and SGB modes, need to investigate.

Gem Gem

(GEN) Secret names (added 16.05.17):
Enter one of these words as a player's name.
たまやま-Sound test.
Source: makainyumon.web.fc2.com

(BUR) Game genie (added 16.05.17):
There are a lot more Secret names were planned, or was removed in the release version. This is unknown what names exactly they used before, all letters are erased now, but with this codes you can make simple replacement to use as the Secret name and get the corresponding effect. Note, the rest of the name should be filled with special SPACE symbol.
011‑E2D‑E6A-Secret name "あ___" - Area 2 warp
021‑EAD‑E6A-Secret name "い___" - Area 3 warp
031‑F2D‑E6A-Secret name "う___" - Area 4 warp
041‑FAD‑E6A-Secret name "え___" - Area 5 warp
052‑0AD‑E6A-Secret name "お___" - Ending

Genki Bakuhatsu Gambaruga

(GEN) Unlock extra multiplayer characters (added 02.05.17):
At the title screen, choose "たいせん" ("Taisen") mode (linked multiplayer), then at the character selection screen, highlight "ガンバルガー" ("Ganbaruga") character and press Right, Left, Right, Left, A, B, A, B. Two new characters "ゴクアーク" ("Gokuaku") and "ヤミノリウス" ("Yaminorius") will be available to select as playable fighters. This code is unlockable and given to you after completing the game for the first time.

Ghostbusters II

Japanese version:

(GEN) Continue screen cheats (added 29.05.17):
Start a new game, loose all lives. After the game over screen at the Continue menu, put cursor to the "END" option, then hold Select and press one of the buttons from table below to get the corresponding effect.
A-Ending
B-Sound test
Source: makainyumon.web.fc2.com

GI King! - Sanbiki no Yosouya

(GEN) Girl opponents (added 22.04.17):
At the title screen, press A + B + Start.
Source: urawaza.in

(UNI) Sound test (added 22.04.17):
Hold Down, then power the console on.

Ginga - Card & Puzzle Collection (Tornado Appetizer)

(UNI) Test menu (added 29.05.17):
Any time during the game, hold Up + Left, then do Soft-reset (A + B + Select + Start at the same time). The menu allows you to listen to the music and sound effects, see the Stage complete animations and the Staff roll.

Go Go Ackman

(UNI) Title screen cheats (added 30.05.17):
At the title screen, hold one of the button combinations from the table below, then press Start to get the corresponding effect.
A + B + Select-All powerups
B-Stage select

Go! Go! Hitchhike

(GEN) Cart RAM clear (added 31.05.17):
At the title screen, press H, Down, B. You'll be prompted whether you want to erase the saves on the Cart RAM or not.
Source: urawaza.in

Go! Go! Tank

(GEN) Title screen cheats (added 01.06.17):
At the title screen menu, press Left, Up, Right, Up, Left, Left, Up, Right, Up, Left, Up. Now the cheat mode is enabled. Available options are described in the table below.
Press Left once.-Enable invulnerability.
Press Right once.-Extra 7 lives at the game start.
Press B up to 10 times.-Select a starting Stage.
Source: urawaza.in

Goal! (USA, Europe), Jaleco J.Cup Soccer (Eerly Japan), Takeda Nobuhiro no Ace Striker (Japan, Rerelease)

All Japanese versions:

(UNI) Debug menus:
All cheats should be entered at the title screen, before the message "PUSH START BUTTON" appears. Also all codes should be entered quickly, without pauses between two buttons. Note, there are two title screens in the Rerelease version, code should be entered on the first one.

US version:

(UNI) Game genie:
001‑9CF‑E6E-In the US version the debug menu button sequences are disabled, but all conding and data are still in the ROM. Use this code to enter the complex debug menu at the game boot. To access the simple menu version, additionally to this code set the RAM address 0xC100 to 1.
Source: tcrf.net

Godzilla (USA), Godzilla-kun - Kaijuu Daikessen (Japan)

(GEN) Sound test (added 01.06.17):
During the game, hold A + B + Start, then press Select.
Source: urawaza.in

(UNI) Secret passwords (added 01.06.17):
Enter one of following passwords in "PASSWORD 18" mode to see one of the developer's messages. Note, "_" symbol means you need to skip this char with "->" arrow.
D#RR=N___ C/#TS____ (for the US version only)-Message to Coats
&?K1N/R1_ T/_N/R1=_ (for the US version)
YUK1N0R1_ T0_N0R1E_ (for the Japanese version)
-Message to Nori
PR/GR#M=R S_FR1=NDS (for the US version)
PR0GRAMER S_FR1ENDS (for the Japanese version)
-Message to Friends
TEST_____ PLAYERS__ (for the Japanese version only)-Message to Test players

(UNI) Cheat mode (added 01.06.17):
Enter any of the Secret passwords described above. During the game, press Select to get to the game menu. Hold A + B and press one of the following combinations to get the corresponding effect.
A-Toggle invulnerability on or off.
A + Right-Jump right on the level's map.
A + Left-Jump left on the level's map.
A + Up-Jump up on the level's map.
A + Down-Jump down on the level's map.

Golf

(GEN) Training mode (added 04.06.17):
At the title screen, for "1PLAYER" option, hold Down, then press Start to start a new game in a Training mode.
Source: gamefaqs.com

(GEN) Cart RAM clear (added 04.06.17):
At the title screen, press Select to go to the Records screen. Hold A + B, then enter Up, Down, Left, Right.

Goukaku Boy GOLD - Shikakui Atama o Maruku Suru - Kanji no Tatsujin

(UNI) Unlock Devil tournament (added 06.06.17):
At the starting logo screens, before the title screen appears, press Left, Left, Right, Right, Down, Down, B. A sound will confirm correct code entry. In the main game's menu, the menu option "?" will appear, enter it and after a short briefing it will turns to a secret "まおう大会" game.

Goukaku Boy GOLD - Shikakui Atama o Maruku Suru - Keisan no Tatsujin

(UNI) Unlock Devil tournament (added 06.06.17):
At the starting logo screens, before the title screen appears, press Left, Left, Right, Right, Down, Down, B. A sound will confirm correct code entry. In the main game's menu, the menu option "?" will appear, enter it and after a short briefing it will turns to a secret "まおう大会" game.

Goukaku Boy Series - 99 Nendo Ban Eitango Center 1500

(BUR) Hidden text (added 03.03.17):
There is a hidden copyright string at 0x61 in the ROM:
1997 April. complete.Making by C-lab.co.,ltd.


Goukaku Boy Series - Eijukugo Target 1000

(BUR) Hidden text (added 03.03.17):
There is a hidden copyright string at 0x61 in the ROM:
1997 Feb. complete.Making by C-lab.co.,ltd.


Goukaku Boy Series - Eiken 2kyuu Level no Kaiwa Hyougen 333

(BUR) Hidden text (added 02.08.18):
There is a hidden copyright string at 0x61 in the ROM:
PROGRAMMED BY hide@sun-tec.co.jp


Goukaku Boy Series - Eitango Target 1900

(BUR) Hidden text (added 03.03.17):
There is a hidden copyright string at 0x61 in the ROM:
1997 October complete.Making by C-lab.co.,ltd.


Goukaku Boy Series - Gakken - Kanyouku Kotowaza 210

(BUR) Hidden text (added 27.09.17):
There is a hidden copyright text at 0x61 in the ROM:
PROGRAMMED BY TOKI


Goukaku Boy Series - Gakken - Rekishi 512

(BUR) Hidden text (added 02.08.18):
There is a hidden copyright text at at 0x61 in the ROM:
PROGRAMMED BY minoru(7/30-0)


Goukaku Boy Series - Gakken - Yojijukugo 288

(BUR) Hidden text (added 06.06.17):
There is a hidden copyright text at the beginning of the ROM:
PROGRAMMED BY TOKI


Goukaku Boy Series - Kirihara Shoten Hinshutsu Eibunpou Gohou Mondai 1000

(BUR) Hidden text (added 14.06.17):
There is a hidden credits text at the beginning of the ROM:
PROGRAMMED BY minoru(12/18-0)


Goukaku Boy Series - Koukou Nyuushi Derujun - Chuugaku Eijukugo 350

(BUR) Hidden text (added 01.09.16):
There is a hidden copyright string at 0x61 in the ROM:
1997 May. complete.Making by C-lab.co.,ltd.


Goukaku Boy Series - Koukou Nyuushi Derujun - Chuugaku Eitango 1700

(BUR) Hidden text (added 01.09.16):
There is a hidden copyright string at 0x61 in the ROM:
1997 April. complete.Making by C-lab.co.,ltd.


Goukaku Boy Series - Koukou Nyuushi Derujun - Kanji Mondai no Seifuku

(BUR) Hidden text (added 02.08.18):
There is a hidden copyright string at 0x61 in the ROM:
PROGRAMMED BY TOKI


Goukaku Boy Series - Koukou Nyuushi Derujun - Rekishi Nendai Anki Point 240

(BUR) Hidden text (added 02.08.18):
There is a hidden copyright string at 0x61 in the ROM:
1997 May. complete.Making by C-lab.co.,ltd.


Goukaku Boy Series - Koukou Nyuushi Derujun - Rika Anki Point 250

(BUR) Hidden text (added 02.08.18):
There is a hidden copyright string at 0x61 in the ROM:
PROGRAMMED BY minoru(7/30-0)


Goukaku Boy Series - Nihonshi Target 201

(BUR) Hidden text (added 03.08.18):
There is a hidden copyright string at 0x61 in the ROM:
1997 October complete.Making by C-lab.co.,ltd.~


Goukaku Boy Series - Shikakui Atama o Maruku Suru - Kokugo Battle Hen

(BUR) Hidden text (added 03.08.18):
There are two hidden copyright strings at 0x61 and 0x000080 in the ROM:
PROGRAMMED BY TOKI
and
Programmed by kuny / 2001.05.09.ver.1.00.( T-T)/


Goukaku Boy Series - Shikakui Atama o Maruku Suru - Rika Battle Hen

(BUR) Hidden text (added 03.08.18):
There is a hidden copyright string at 0x61 in the ROM:
Programmed by kuny / 2001.05.09.ver.1.00.( T-T)/


Goukaku Boy Series - Shikakui Atama o Maruku Suru - Sansuu Battle Hen

(BUR) Hidden text (added 03.08.18):
There is a hidden copyright string at 0x61 in the ROM:
PROGRAMMED BY minoru(9/14-0)


Goukaku Boy Series - Shikakui Atama o Maruku Suru - Shakai Battle Hen

(BUR) Hidden text (added 03.08.18):
There are two hidden copyright strings at 0x61 and 0x000080 in the ROM:
PROGRAMMED BY TOKI
and
Programmed by kuny / 2001.05.09.ver.1.00.( T-T)/


Goukaku Boy Series - Shikakui Atama o Maruku Suru - Suuji de Asobou Sansuu Hen

(BUR) Hidden text (added 03.08.18):
There is a hidden copyright string at 0x61 in the ROM:
PROGRAMMED BY minoru(2/19-0)


Goukaku Boy Series - Yamakawa Ichimonittou - Nihonshi B Yougo Mondaishuu

(BUR) Hidden text (added 03.08.18):
There is a hidden copyright string at 0x61 in the ROM:
Making by C-lab.


Goukaku Boy Series - Yamakawa Ichimonittou - Sekaishi B Yougo Mondaishuu

(BUR) Hidden text (added 03.08.18):
There is a hidden copyright string at 0x61 in the ROM:
Making by C-lab.


Goukaku Boy Series - Z Kai - Kyukyoku no Kobun Tango

(BUR) Hidden text (added 03.08.18):
There are a couple of hidden copyright strings at 0x76 in the ROM:
Produce by imagineer
Program by Minoru-N
1998-08-18 Start.


Gradius - The Interstellar Assault (USA), Nemesis II - The Return of the Hero (Europe), Nemesis II (Japan)

(BUR) Game genie (added 07.06.17):
CDE‑7DF‑E65+00E‑84F‑E69 (for the US version)
CDE‑45F‑E65+00E‑4CF‑E69 (for the Japanese version)
-Re-enables the unsed "DEMO" screen, possibly used for Prototype builds.

Grander Musashi RV

(GEN) Cart RAM clear (added 08.06.17):
At the title screen, press Left, Left, Right, Right, Up, Up, Down, Down, B. A sound will confirm correct code entry.

Great Greed (USA), Vitamina Oukoku Monogatari (Japan)

(GEN) Unlockables (added 07.06.17):
Complete the game to unlock Sound test and Monsters book.
Source: gamefaqs.com

(BUR) Hidden text (added 07.06.17):
There is a generic Namco copyright text at the beginning of the ROM, partially used for RAM initialization signature:
COPYRIGHT 1992 NAMCO LTD. ALL RIGHT RESERVED


HAL Wrestling (USA), Pro Wrestling (Japan)

(GEN) Continue (added 08.06.17):
At the title screen, select "1 PLAYER" mode, hold Up + Select and press A. Now, when loose any round, you'll start fighting from the beginning with current character instead of jump to the game over screen.
Source: urawaza.in

Hammerin' Harry - Ghost Building Company (USA), Daiku no Gen-san - Ghost Building Company (Japan)

(FIX) Stage select (added 08.06.17):
At the title screen, when the "PUSH START" message is displayed, press and hold A + B + Up + Right + Start. While holding all these buttons, wait for the screen turns blank. Now, press Select a number of times corresponding to the desires starting Stage number from 2 to 19 (including bosses). Every time you press Select a sound effect will be heard.
Source: jp.wazap.com

(GEN) Pause cheats (added 08.06.17):
During the game, press and hold A + B + Select + Start. If done right, the background music won't fade. While holding all these buttons, enter one of the combinations from the table below to get a corresponding effect. Every time you press the correct button in sequence, various game sound effects will play. If one of the buttons pressed incorrectly, then music will fade, and game jumps to generic pasue mode, so you should press Start here and enter all codes again.
Right, Left, Right, Left, Down, Down, Up, Up-Refill health.
Up, Down, Up, Down-Instant Game over.
Down, Down, Down, Down, Up-Toggle the Slow down mode on or off.

(BUR) Hidden text (added 08.06.17):
Here is a hidden version string at the beginning of the sound engine code, the same an all regional versions:
** Ver 6.04 **

Source: tcrf.net

Harvest Moon GB (USA), Bokujou Monogatari GB (Japan)

(BUR) Game genie (added 23.07.16):
001‑E3F‑6EA
1FF‑819‑E66 (additional code for the US version)
-Re-enables a complex debug menu. In the Japanese version it is fully functional, the US version however has most of the options disabled and invisible. Use additional code to re-enable all options somehow in the US version.
Source: tcrf.net

Hayaoshi Quiz - Ouza Ketteisen (The King of Quiz)

(GEN) Secret game (added 09.06.17):
At the title screen, press Up, Up, Left, Left, A, B, Down, Start. A new option will appear in the bottom-left corner of the main game's menu.
Source: urawaza.in

(BUR) Game genie (added 09.06.17):
1A1‑7EB‑F7A-Re-enables the Quiz test mode. Select the theme with Up/Down, a question with Left/Right and display it along with the correct answer indication with A. Press Start to exit back to the title screen.

Heavyweight Championship Boxing (USA), Boxing (Japan)

All versions:

(UNI) Maximum power (added 27.07.16):
Start either a new single player or a two players game. At the player's character selection screen press Up three times and Down three times in any order and finally press Select. Continue to setup your character. At the Power management screen, press Up 3 more times and then Select. If done right, the main power meter will be full and you'll be able to set up the max parameters to your character.

(UNI) Extra 255 continues (added 27.07.16):
Start a new single player game. At the Finish blow select screen, hold Down + Select + Start, then press A. If done right, the limit of the continues will be increased up to 255 instead of 3, so virtually you'll have an unlimited continues.

Japanese version:

(UNI) Easter egg (added 27.07.16):
Start a new single player game. As you may notice, the Round number screen will show you the Bunny girl scrolled higher and higher up with every round. The maximum position reached at 12th round. While 12th round screen is displayed, hold Down and quickly press A or B to scroll the Bunny girl up to 24 more lines, revealing the full picture. Althought the US version has this girl fully drawed as well, the easter were removed and you couldn't see the full picture during the game.

Heisei Tensai Bakabon

(GEN) Suicide (added 12.06.18):
In-game, hold Select then press Start to commit suicide.
Source: urazawa.in

Hercules

(GEN) Secret passwords (added 10.06.17):
CRDTS-Credits.
Source: gamefaqs.com

Hero Shuugou!! Pinball Party

(UNI) Secret message (added 13.06.17):
At the "GAME MODE SELECT" screen, enter "SOUND BOY" mode. Choose "PROGRAM PLAY" mode and set any sequence of the music tracks to play. Start to play the program either in "THROUGH" or "REPEAT" modes, no matter. There is a piglet character walking on the screen all the time the music is playing. At some point, this piglet will stop and make a bow to the player for a very short time. Press A + Start at exactly that moment. This may be tricky, but if done right the message "BU !" will appear above the piglet. This "SOUND BOY" was reutilized later in another game by the same developer: "Ikari no Yousai".

(BUR) Extra Much push attempts (added 13.06.17):
When the "GAME OVER!!" message is displayed on the screen, press A + B + Select. This will gives to you an extra 3 "MUCH PUSH A" bonuses during the game. However, this bonus happened only right before the Game over, so you just couldn't use all three of them in one run. When you return to Continue screen, the bounus counter will be reset to the default value 01 or may be restored to 03 with this cheat again. So, all this it seems mostly useless.

Hiden Inyou Kikouhou - Ca Da

(UNI) Sound test (added 22.07.16):
At the title screen, press Down + B.

Higashio Osamu Kanshuu Pro Yakyuu Stadium '92

(GEN) Secret teams (added 13.06.17):
At the Team select screen, while selecting CPU team, press Up + Select. If done right, an extra 3 special teams select screen will appear.
Source: urawaza.in

High Stakes Gambling

(UNI) Credits (added 13.06.17):
At the title screen, press Select + B.

Hit the Ice - VHL - The Official Video Hockey League

(UNI) Animations test (added 14.06.17):
Start a new game either in a Championship or VS. Play modes. Before the game starts, when the "PERIOD START" / "FACE OFF" messages are displayed, hold Select + Up for a second until the menu appears. You can see the animation sequences for various game events. There is no exit from this mode, and it seems this is just a debug leftover, which developers forgot to remove.

Hoi Hoi - Game Boy Ban (Japan), Stop That Roach! (USA)

(BUR) Game genie (added 14.06.17):
Both codes replaces the "NEW GAME" option at the title screen with a corresponding test. There were a button codes assigned for both tests, but they are not checking in all release versions. The the US version has additional option in the Anim test allowing you to return to the title screen, which you couldn't in the Japanese version.
B16‑95E‑D59+456‑96E‑D5A (for the US version)
2D6‑44E‑D59+466‑45E‑D5A (for the Japanese version)
-Sound test (Select + Up cheat in the US version, Select + B + Left + Up - in the Japanese version)
3A6‑95E‑D59+466‑96E‑D5A (for the US version)
B66‑44E‑D59+466‑45E‑D5A (for the Japanese version)
-Anim test (Select + Down cheat in the US version, Select + B + Left + Down - in the Japanese version)

Holy Bible, The - King James Version (Wisdom Tree, Unlicensed)

(GEN) Word Match Game Level select (added 18.11.18):
At the Word Match Game Title screen, hold Up, then press Select to increase starting game level.
Source: gamefaqs.com, tcrf.net

(UNI) Checksum test (added 18.11.18):
At the main menu, press Left 8 times. A sound informs you when checksumming started and finished. Then the resulting checksum will be displayed instead of the ROM version on the same screen.

Home Alone 2 - Lost In New York

(UNI) Secret items (added 15.06.17):
There are three Secret items in this game. Each called "[Name] Magic", where "[Name]" is one of the dev names, and gives to you one of the regular power-up items permanently. All of them can be acquired exactly the same way, but in different rooms of the Hotel. To reveal them, go to the rightmost bed in the corresponding room, jump on it not less than 7 times in row (like on the couch in the lobby to get to the upper floor). When landing on the bed for the 7th time, hold Up, then press A + B. The item will fall from the upper-right corner of the screen. The names, the corresponding items and its locations are described in the table below. Note, that jumping may be tricky. But there is a way to do it for sure. Press and hold Up in mid-air every time you jump up. While you holding it, the jumping counter is not resetting, even when you land and stand still on the bed. To perform next jump, release Up for very short time, press A to jump and hold Up immediately again.
Name|Location|Item
Roddy Magic|Hotel floor 11, Room 2|High jump item (Bell)
David Magic|Hotel floor 11, Room 4|Simple invulnerability item (Candy)
Nancy Magic|Hotel floor 14, Room 2|Super invulnerability item (Bottle)

Hon Shougi

(GEN) Cart RAM clear (added 15.06.17):
During the game, open the main game's menu, put cursor to the second option (SAVE/LOAD), hold Select and press A. Select one of two slots to clear and press A again.

Hong Kong

(GEN) Title screen cheats (added 15.06.17):
At the title screen, hold one of the following button combinations and press Start to get the corresponding effect.
A-Sound test.
B-Stage complete animation.
A + B-Hong Kong Block mini-game. Beat 6 stages to see the true game ending.
Source: urawaza.in, gamefaqs.com

Hook

(FIX) Cheat mode (added 15.06.17):
At the title screen, press Right, Up, Up, Down, Down, Right, Left, Up. A sound will confirm correct code entry. There are several options available now. At the title screen, press Left to see the ending. At the Map screen, select location and press Select to skip to in instantly.
Source: gamefaqs.com

Hudson Hawk

(FIX) Title menu cheats (added 16.06.17):
At the title screen, when "PRESS START" message is displayed and when you can choose to ON or OFF the Music and SFX, before the demonstration begins, enter one of the following button sequences. If done right, the "CHEAT SCREEN" will be displayed. You can toggle the cheat mode ON and OFF and return back to the the title screen. When cheat mode is ON, there are a couple of options available during the game, all described in the table below.
Up, Left, Down, Right, Right, Down, Left, Up-Infinite lives
Press Select during the game to kill all enemies on the screen.
Hold B, then press Select to skip current Level part.
Hold B + Up, then press Select to instantly complete current Level.
Also if mode is ON, the demo sequence will play incorrectly.
Source: gamefaqs.com
Select, Select, Select, B, A, B, Start-All effects enabled by the previous cheat.
Invulnerability to all Enemies, its projectiles and deadly objects (including alarm floors). You still can die in the ground pits, but since the lives are infinite anyway, that's not a problem.
Hold Select, then press Start to toggle the Level view mode using the D-Pad button. However, this doesn't mean you can put your character at any position of the level.

Hugo 2

(UNI) Secret message (added 21.06.17):
Complete the game on the "SCHWER" ("Hard") difficulty without losing any lives and with not less than 50 gold bags collected during the game (only the completed levels counts). Then after the Credits roll you'll see an addiotional dedication screen with name: "JANINE LEA".

(UNI) License screen cheats (added 21.06.17):
At the License screen, enter the button sequence A, B, Left, Down, Right, Up, A a number of times corresponding to the desired cheat described in the table below. Note, every time you complete one sequence, a sound will play. Worth to mention, that the cheat test code meant to have 3 different codes which you need to input one after another to enable the cheat with a corresponding number, but in the release version all three sequences are the same so you just need to repeat them.
1 Time-Infinite lives in all Stages
2 Times-In the Woods level, the Logs won't kill you anymore.
3 Times or more-Unused, does nothing.

(BUR) Game genie (added 21.06.17):
0_A‑71F‑E66-Use the codes, where "_" is the number from 0 to 2 to switch the game to a different languages (English, Portugese and French correspondingly). The game has default language hardwritten in the ROM - 3 (German). Most of the Language tables are points to the same German phrases, only the menu is fully translated (Portugese has a bug in it, however), as well as the intro phrase for all other languages is "GAME OVER".

Humans, The

(GEN) Sacrifice (added 22.06.17):
During the game, on any level, except levels 1, 7 and 21, press Select + Down to open the Sacrifice menu. You can exchange one or more humans to one of the tools instantly.

Hunchback of Notre Dame, The - Topsy Turvy Games

(GEN) Secret passwords (added 22.06.17):
This password is for the Chiseler game mode only. After entering this password, the game will return to the password entry screen without any indication.
PSCGM-Cheat mode. During the game, press A to increase amount of lives. Press Select to skip to the next stage.
Source: tcrf.net, gamefaqs.com

(FIX) Secret passwords (added 22.06.17):
There is a complete list of FunFair tickets. At some point during any of 5 mini-games you can unlock the Challenge mode for a corresponding game. Then the game will generate the Tickets which contains info about all unlocked Challenges. Upon entering the Ticket in a FunFair mode, the Wheel of Fortune will randomly select one of the unlocked games to play random Challenge. In the table below, "P" stands for "Picture Puzzle", "U" - "Upsy Daizy", "F" - "Catch the Fool", "D" - "Djali Bowling" and "C" - for "Chiseller", "+" means the corresponding game is unlocked in a particular Ticket.
Ticket|P|U|F|D|C|
04419|-|-|-|-|+|Source: gamefaqs.com
75939|-|-|-|+|-
95567|-|-|-|+|+
76431|-|-|+|-|-|Source: gamefaqs.com
75407|-|-|+|-|+
55762|-|-|+|+|-
41403|-|-|+|+|+
59269|-|+|-|-|-
38793|-|+|-|-|+
44722|-|+|-|+|-
76792|-|+|-|+|+
54146|-|+|+|-|-
13258|-|+|+|-|+
10017|-|+|+|+|-
59657|-|+|+|+|+
41389|+|-|-|-|-
41858|+|-|-|-|+
19566|+|-|-|+|-
83203|+|-|-|+|+
25112|+|-|+|-|-
58415|+|-|+|-|+
34693|+|-|+|+|-
24872|+|-|+|+|+
41984|+|+|-|-|-
75478|+|+|-|-|+
30434|+|+|-|+|-
68066|+|+|-|+|+
67782|+|+|+|-|-
83840|+|+|+|-|+
39074|+|+|+|+|-
11320|+|+|+|+|+

Hunt for Red October, The

(GEN) Stage select (added 23.06.17):
At the title screen, press B, Select, Left, Right, Start.
Source: gamefaqs.com

(FIX) Course map cheats (added 23.06.17):
At the course map screen, hold A + B, then enter one of the following cheat sequences. They cannot be combined, so choose wisely.
Select, Up, Down-Extra 25 lives
Up, Down-Extra 25 missiles
Left, Right-Extra 25 cloaks
Source: gamefaqs.com

Hyper Lode Runner

(UNI) Password generator (added 23.06.17):
Level:
Use counter:
Random:
Password:


Ikari no Yousai 2

(GEN) Secret passwords (added 26.06.17):
"ANAI "-SD mode, girl head 1.
"MAI "-SD mode, girl head 2.
"BOSS2"-SD mode, girl head 3.
"VIVA!"-Girls dance screen, then Ending.
Source: gamefaqs.com

Incredible Crash Dummies, The

(GEN) Cheat mode (added 26.06.17):
At the title screen, press Up, Down, Left, Right to activate the cheat screen. Now enter any of these passwords from the table below.
57481235-Day 1
32054573-Day 2
29643724-Day 3
12715632-Day 4
58328765-Day 5
46875973-Easy difficulty
63442196-Normal difficulty
92347232-Hard difficulty
81212337-Very hard difficulty
56378152-Sound test
Source: tcrf.net, gamefaqs.com

Initial D Gaiden

(UNI) Unlock all (added 27.06.17):
Hold A + B + Select + Left + Down, then power up the console and wait until the title screen appears. This will unlock all 4 scenarios, 2 extra courses and 7 extra cars instantly.

Iron Man X-O Manowar in Heavy Metal

(FIX) Secret passwords (added 30.06.17):
LSLSDB-Enables the debugging features.
During the game, press Start to pause, hold either A or B then press Start again to enter the Stage select menu.
Either on pause or during the game, hold Left and press Start to toggle the Stage select cheat OFF and ON again. A sound will be heard instead of toggling the Pause mode.
During the game, hold B + Start then press Up or Down to free move your character vertically at current horizontal position. Also, if you hold the same buttons mid-air while dodging after the enemy bullet hit, you can do the same horizontally but only inside current screen. However, due to hacky controls programming method, if you press Up being in free horizontal movement state you switch to free vertical movement state and couldn't control the horizontal movements anymore, but still have a horizontal velocity. So you can free walk through the level somehow. Also, being in a free movement state you are completely invulnerable, as well you won't meet bosses anymore.
Source: gamefaqs.com

Ishidou - The Way of Stones

(UNI) Auto play (added 30.06.17):
At the title screen, setup any game mode and options, press Start then immediately hold A + B + Select + Start + Right for the Japanese version and A + B + Select + Right for the US version, then wait until the screen fades out.

Itchy & Scratchy - Miniature Golf Madness

(FIX) Title screen cheats (added 03.07.17):
At the title screen, enter one of the following cheats to get a corresponding effect. A sound will confirm correct code entry. Cheats may be combined.
Select, A, Down, B, Up, Down-Empty cheat, does nothing, only sound can be heard for it.
Right, A, Down, Right, A, Down-Invulnerability.
Select, Up, Up, Select, Left, Left-Stage select.
Source: gamefaqs.com

Itsudemo! Nyan to Wonderful

(BUR) Hidden text (added 03.07.17):
The Cart RAM initialization routine uses following string at 0x39065 in ROM as a save data signature:
BUP MEMORY INITIALIZED V.14

Source: tcrf.net

J.League Fighting Soccer - The King of Ace Strikers

(GEN) Auto play (added 04.07.17):
At the "HALF" selection menu for the "TEST PLAY" mode or at the "CONTINUE/START" menu of either the "TOURNAMENT" or "LEAGUE" modes, hold Select + Start, then press A. Now, both players will be CPU controlled and play automatically.
Source: urawaza.in

(BUR) Hidden text (added 04.07.17):
The Cart RAM initialization routine in this game uses a programmer's nickname as RAM signature:
SILPHEED


Jack Nicklaus Golf

(UNI) Secret message (added 11.07.17):
At the title screen, wait for "A SCULPTURED SOFTWARE presents" window starts to scroll out, hold Start + Select + Left and wait for the license window appear. Continue holding all the buttons about 7 seconds after that until the series of the secret dedication messages are displayed.
Source: tcrf.net

James Bond 007

(GEN) Secret names (added 15.07.17):
Enter one of these words as a player name when registering a new Save game slot. All names are unlockable and given to you after the credits screen when the game is beaten.
BACCR-Baccara mini-game
BJACK-Blackjack mini-game
REDOG-Red Dog mini-game
Source: gamefaqs.com

(BUR) Game genie (added 15.07.17):
0C1‑85F‑C46+F91‑8CF‑5D+701‑8DF‑B3B-Re-places the title screen with an unused version screen "JAMES BOND 11:23:97A", most probably a leftover from the developement stage.

Jankenman

(FIX) Ending (added 01.09.18):
At the Stage select screen, hold Right + A then perss Start.
Source: urawaza.in

Jelly Boy

(UNI) Secret passwords (added 06.09.17):
Upon entering a secret password a message "CHEAT ACTIVATED" will be displayed, then program will wayt for any other password input, so secret passwords can be combined together or with any other valid password.
94737921889254-Extra 10 lives, extra 1 note at the beginning of the level.
SFVGHVRLHDKNLT-Extra 20 lives.
NDSGVBQXCDCPHG-Does nothing, rises an unused cheat flag.
CHVBDTHDFHLNMS-Unlocks all rooms.
KRC-FGBB809HRB-Enables the free walk in the level map mode.

Jetsons, The - Robot Panic

(BUR) Game genie (added 11.09.17):
00F‑50C‑C4D-Re-enables the invulnerability toggle cheat. Any time during the game just press Select to either switch the invulnerability on or off.

Jikuu Senki Mu

(BUR) Game genie (added 12.09.17):
50A‑E28‑E6B-Replaces ingame menu option "CHANGE" with the "DEBUG DATA SET" menu. It allows you to change any area or item flags as well as warp to any town. There should be a button code to enter this menu when you enter the "CHANGE" option (hold Start + A). But the corresponding branch instruction in the final version were removed, so button code doesn't work.
201‑7DA‑80E-Re-enables the Instant Flee button code. During the monster battles, hold Start + Select then choose "FLEE" option from the battle menu to skip any battle instantly.

Jinsei Game

(UNI) Same human-controlled players (added 14.09.17):
While selecting 2 or more human-controlled players, normally you cannot selected the same character for different players. But, you actually can do it if hold Select + B. This does not applied to the CPU controlled players.

(BUR) Game genie (added 15.09.17):
7C1‑EAF‑08E+081‑EBF‑B36-Re-enables the Debug menu activation code. During the game press Select to open the debug menu. Note, some portions of the game has no proper font loaded unless you at any message or menu screen.
292‑70F‑91B+5C2‑71F‑6EB+059‑46A‑F72-Re-enables unused game setup screen intended to be called after the name entry but before the game. This screen asks all players to choose a card and then decide the turns order. The code is fully working except the order isn't used by the game anyway. All players are moving according to it's numbers in the list. Note, that this hack is overwrites the ending screen.
25A‑9CB‑804+4CA‑9DB‑C46-Replaces the empty dummy handler for "SCROLL TEST" in Debug Menu with otherwise not mentioned anywhere else "SPRITE TEST". The test is rather simply just like the "CHR TEST", and only allows you to see one single sprite with some animation using currently loaded tiles for sprites.
Source: tcrf.net

Joe & Mac (USA), Joe & Mac - Caveman Ninja (Europe)

(BUR) Game genie (added 18.09.17):
047‑C99‑E62+047‑519‑E62 (for the US version)-Re-enables the language select and the music on/off options in the main game menu.
045‑DA9‑E66+046‑4C9‑E66 (for the European Version)-Re-enables missing music on/off option in the main game menu.

Joshua (Wisdom Tree, Unlicensed)

(UNI) Debug mode (added 18.11.18):
At the title screen, enter the Sound test mode. Put cursor to "JOSHUA HAS TO START OVER" option, press Left. Then, put cursor to "JOSHUA EXITS LEVEL" option and press Right. If done right, the "WON THE GAME" music teme starts to play automatically. From now, there are several options available.
At the title screen, press either Left or Right at least once to activate a debug CPU-meter during the game. It will be displayed instead of current stage number in the game's HUD.
At the Stage number screen:
Press Start to increase lives.
Press Select to get extra 100 Trumpets and set weapon to max power and range.
Also level selection with Up/Down skips stage by 1 instead of 5. Max level value increased from 81 to 110 which includes all 100 game levels as well as 10 bonus levels.


(UNI) Secret passwords (added 18.11.18):
ADAM-Enter this password then press Select + B instead of A. This enables the same Debug mode described above but you just can't activate the CPU-meter from here.
FQUE-Bonus level 1. Note, this and all following passwords are not available during the game even using the Debug mode cheat to select them manually at the Stage number screen.
CJEU-Bonus level 2
JTJS-Bonus level 3
XJKC-Bonus level 4
AGSB-Bonus level 5
JMMP-Bonus level 6
GZZW-Bonus level 7
BLPK-Bonus level 8
YQEH-Bonus level 9
HPNJ-Bonus level 10

Judge Dredd

(GEN) Stage select (added 18.09.17):
At the title screen, press A, Left, Right, Left, Right, B. A sound confirm correct code entry. The Stage select screen will appears before the the new game starts.
Source: gamefaqs.com

Jurassic Park

(GEN) Stage skip (added 21.09.17):
At the main game menu, press Up, Down, Left, Up, Down, Right, Select, Up, Down, Left, Up, Down, Right, Select. A sound will confirm correct code entry. During the game, either hold Select and press Start, or press Start, then press Select once (in this case sometimes code doesn't work) to skip to the next level.
Source: gamefaqs.com

Jurassic Park 2 - The Chaos Continues

(GEN) Stage skip (added 23.09.17):
Pause the game, press Up, Down, Left, Right, A, B, Up, Down, Left, Right, A, B. A sound will confirm correct code entry. Being in pause mode, hold Select, then press Start to skip to the next Stage.
Source: gamefaqs.com

(BUR) Hidden text (added 22.09.17):
There is a build date string and the very beginning of the ROM:
 28 SEPTEMBER 1994     


(BUR) Game genie (added 23.09.17):
001‑66C‑80A+001‑67C‑B36-Re-enables some weird debug leftover. Enable the Stage skip cheat as described above, then press A + B + Select to reset the game with some weird screen effect.
001‑9DC‑C4D-Also for the Stage skip cheat re-enables additionally a Hearts restore button code. Hold A, then press Start to refill hearts.

Kachiuma Yosou Keiba Kizoku (Japan), Kachiuma Yosou Keiba Kizoku Ex'94 (Japan, Rerelease), Kachiuma Yosou Keiba Kizoku Ex'95 (Japan, Rerelease)

(GEN) Credits (added 25.09.17):
For the regular version of this game, at the title screen, hold B + Select + Up and press A. For the "EX" versions, you need to hold A + B + Select + Up at once at the "KING" logo then wait until the screen fades out.
Source: urawaza.in

(GEN) Cart RAM clear (added 25.09.17):
For the regular version, when "BACKUP RAM CHECK" is displayed, press Select to erase all saved data instantly. For the "EX" versions, on the powered off console, hold Select + Start, then power it on.

Kaeru no Tame ni Kane wa Naru

(GEN) Cart RAM clear (added 25.09.17):
At the title screen menu, press Down + Right + B to clear the saves data.

Kaguya Hime Pachinko

(UNI) Debug cheats (added 25.09.17):
During the game, upon entering any pachinko machine press Start once, then one more time to begin to input one of the following button sequences. If you already entered any cheat, just press Start once to begin to enter it again. When input is finished, press Start to complete the code. A sound will confirm correct code entry. These codes are toggle the corresponding debugging flags on an off. You can enable more than one at once. Some of cheats does nothing because the corresponding debugging handlers are disabled and never called. However, those cheats may be entered and raise the corresponding flags.
Up, Up, Down, Down, Right, Left, Right, Left, Up, Up, Down, Down, Right, Left, Right, Left-(1) Instantly enables the "RAKU RAKU PACHIN" item during the game which normally should be bought in the items shop. Press A to stop the balls. Lever is stand still. Effect is permanent for all machines and can be disabled only by using the corresponding item of after the game over screen.
A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A-(2) Instantly starts the "Jackpot" state for current machine.
Up, Down, Left, Right, Up, Down, Left, Right, Up, Down, Left, Right, Up, Down, Left, Right-(3) Displays current lever position at the bottom-right corner. Also disables screen flashing when sink the ball into the hole. Effect is permanent for all machines.
Left, Down, Left, Left, Left, Down, Left, Left-(4) Does nothing.
A, A, A, A, A, B, B, B, B, B, A, A, A, A, A, B, B, B, B, B-(5) Does nothing.
B, B, B, B, B, B, B, B, B, B, B, B, B, B, B, B, B, B, B, B-(6) Enables adjusting machine speed. Press Up/Down do adjust the speed. Press A to set maximum speed (0). Press B to reset to the defaul machine speed. Effect is permanent for all machines.
Up, Right, Up, Right, A, B, A, B, Up, Right, Up, Right, A, B, A, B-(7) At the machine info/start menu, press Start to select any machine type or hold Select and press A to instatnly beat selected pachinko machine. Also disables random pachinko machines difficulty tossing upon starting a new game after the game over screen. Effect is permanent.
B, B, Right, Left, B, B, Right, Left-(8) Does nothing.

(BUR) Game genie (added 26.09.17):
Note, each pair of codes here are replaces the same 6th cheat handler with one of the disabled handlers. So you won't be able to use Speed adjust cheat here and can't re-enable all cheats at the same time.
DF5‑8B8‑08E+765‑8C8‑3B7-Restores the 4th cheat handler. This was some kind of Timer mini-game, unfortunately it seems unfinished and does not work properly. When triggered, both the machine and the player gives 2000 balls instantly and a current stage number and a timer are displayed at the bottom-right corner (timer interrupt should be used but never enabled in the current code so timer doesn't increment at all). The game will play intil some predefined timer value then stop and check the results.
E85‑8B8‑08E+755‑8C8‑3B7-Restores the 5th cheat handler. This allows you to adjusted several machine probability values, mostly used for calculating a chance to ball to sink into the particular hole. Use D-Pad to set any of 7 values from 01 to 99. Press Start to return back to the game.
805‑8B8‑08E+765‑8C8‑3B7-Restores the 8th cheat handler. It were used for adjusting the timer stop value for the Timer mini-game mentioned above. Use D-Pad then press Start to apply settings.

Kaijuu Ou Godzilla

(GEN) Sound test (added 02.06.17):
At the first title screen, press Select.

(UNI) Debug screen (added 02.06.17):
During the game, press Start to pause it, then press Up, Down, Up, Down, A, B, Right, Left, B, A, Down and additionally any button one more time. Here you can change the stage number, lives of the godzilla and more. Press B to exit back to the game. Press Select during the game to open Debug screen instantly.

Kamen Rider SD - Hashire! Mighty Riders

(BUR) Game genie (added 06.08.18):
358‑CAE‑4CE+288‑CBE‑91E+04B‑8CE‑E6E-There is an unused debug menu tile-map resource. However, there is no CHR data and proper code handler for this menu at all in the ROM. Also there is some kind of stage selection routine which even can display a number on the screen but have no proper caller and other corresponding code so in fact it is non functional. However, combining both leftovers we could see somehow the menu and the selection screen at once. So use three codes and enter the first option at the title screen. Since there is no proper font for menu letters, you actually can only see the options positions and a number at the bottom which correspond to stage select routine. The actual menu should look likie this:
     SD RIDERS


      1P START
      2P START
      2P FRAME TEST
      2P RANDOM TEST

Kandume Monsters

(UNI) Message test (added 26.09.17):
At the title screen, press Select, Left, Right, B, B, Down, Up, Select, B, Up. A sound will confirm correct code entry. 4th menu option will be added to the left of the main menu options. Select it to access the message test mode.

(UNI) SGB 2P battle (added 26.09.17):
This cheat is accessible only in SGB mode. First, enter the Message test cheat. Then leave the title screen (select "OPTIONS") and return back (this should reset the internal cheat counters). Now enter Select, Select, Select. A sound will confirm correct code entry. 5th menu option will be added to the right of the main menu. Select it to play 2P Battle mode on SGB controllers.

(UNI) Game genie (added 26.09.17):
226‑83F‑6E9+636‑84F‑5DB-Replaces ingame "HELP 1" screen with an unused disabled Parameters editor. You'll be able to modify any monster parameter and play again.

Karakuri Kengou Den Musashi Lord

(BUR) Game genie (added 03.10.17):
011‑8BF‑E6A-Enables the Debug features.
At the title screen:
Put cursor to "START" option, press Up to select starting stage.
Press Select to cycle through the SE/BGM indexes, press B to play it.
During the game:
On pause, every A press increments HP and adds 10 money.
At items menu, press Left 4 times, exit menu to toggle the Free Walk. Also you will be invulnerable for all enemies and obstacles except water.
Source: tcrf.net

Karamuchou no Daijiken

(UNI) Cheat menu (added 03.10.17):
At the title screen, press Select, Up, Down, B, Left, Start. You'll be able listen to the sounds and music, watch cutscenes including ending and staff roll, set invulnerability or select any stage. The "PAUSE" option enables the pause button code: during the game hold Select then press Start, press Select to unpause.

Kaseki Sousei Reborn

(UNI) Cheat menu (added 04.10.17):
At the title screen, press Select, Up, Down, B, Left, Start. You can listen to the sounds and music, watch staff of intro sequences, or enable the Pause mode button code (during the game hold Select, press Start, press Select to unpause).

(UNI) Secret names (added 04.10.17):
Enter one of these words as a character name at the name entry screen to switch its current gender. By default it's male. Unfortunately, you couldn't switch genders for your dino-pets.
おとこのこ-Male character.
おんなのこ-Female character.

Kattobi Road

(GEN) Cart RAM clear (added 04.10.17):
Hold A + B + Up, then power on the console.

(BUR) Hidden text (added 04.10.17):
The Cart RAM initialization routine uses as a signature build date string:
IDY 5/27 14:10
Also, there is another completely unused date string inside the ROM:
1993,07,14,15,12


Kenyuu Densetsu Yaiba

(GEN) Continue (added 06.08.18):
At the title screen, press Left, Right, Down, Down, Left, Left, Up, Up, Start.
Source: urawaza.in

(GEN) HP recovery (added 06.08.18):
Pause the game, press Left, Left, Right, Up, Left, Right, Up, Down, then unpause it.
Source: gamefaqs.com, urawaza.in

Kid Dracula (USA), Akumajou Special - Boku Dracula-kun (Japan)

US version:

(FIX) Secret passwords (added 30.04.16):
7314-Sound test
9814-Mid-level minigames.
Source: gamefaqs.com

Japanese version:

(FIX) Secret passwords (added 30.04.16):
まつたけ-Sound test
ふりかけ-Mid-level minigames.
Source: tcrf.net

Kid Icarus - Of Myths and Monsters

(GEN) Cart RAM clear (added 30.06.18):
At the title screen, press Select + B + Left.
Source: gamefaqs.com

(GEN) Black Market Gamble (added 01.07.18):
During the game, at the Black Market Store, press A + B + Left + Down to throw the dice. If you lucky enough, the prices will lower down, if you don't they be risen twice.
Source: gamefaqs.com

(BUR) Hidden text (added 30.06.18):
The Cart RAM signature in this game is word:
KUMI


(BUR) Game genie (added 06.08.18):
010‑03F‑E6A-Re-enables some debug functionality.
During the game, hold Select then press Up to advance to the next stage up to 3-4, or press Down to return back to the previous stage.
While in pause mode, press either A or B to enable simple CHR viewer, press any of these buttons one more time to swap tiles, then once again to return back to pause screen.
At the status menu, now two rows of numbers are displayed under the strength meter, they are the special secret score and the current level score. Also, hold one of the buttons from table below, then press A to get a corresponding effect:
Up-Toggles three sacret treasures from Stage 4.
Down-Toggles NMI sync disable flag. When on, the game does not wait the NMI at the beginning of the main loop. Makes game faster somehow, but only when the main loop is not loaded enough.
Left-Toggles invulnerability.
Right-Maximizes all player's statuses, gives all items and full map.
Source: tcrf.net

Kidou Keisatsu Patlabor (Mobile Police Patlabor) in Nerawareta Machi 1990

(GEN) Easter egg (added 09.08.18):
At the license screen hold A + B + Select + Start and wait for the title screen. Instead a screen filled with word "BABEL" will appear.
Source: urawaza.in

(GEN) Secret staff roll (added 09.08.18):
At the license screen hold Select and wait for the title screen. The secondary title will change to "あめりかへん 1994" ("America Hen 1994"). Now, press Start to watch the Secret staff roll.
Source: urawaza.in,gamefaqs.com

(UNI) Sound test (added 09.08.18):
There is a set of secret passwords with common format: "XX999", where "XX" a decimal number in range from "00" to "10". Upon entering any of it the backround music will change to a corresponding game track.

Kikou Keisatsu Metal Jack

(BUR) Game genie (added 17.01.17):
386‑C5E‑2AA-There is an error handler hidden in a couple of GB/GBC games by the same developer ("Chiki Chiki Tengoku", "Cyber Formula GPX" and many GBC titles). All them are functional, but can't be seen if no errors are happens. Most of that games has its font loading routine removed so you can't see something anyway. Surprisingly, this one particular game has the fonts and its loader intact so you may see this error handlers somehow. Use this code, thep press Start at the title screen.

Killer Instinct

(GEN) Auto player select (added 08.08.18):
At the player selection screen hold Up, then press any of these buttons: A/B/Select/Start. The current player will be selected randomly.
Source: gamefaqs.com

(GEN) Play as Eyedol (added 08.08.18):
At the versus screen, hold Right, then press Select, Start, B, A. A sound will confirm correct code entry. To keep playing this character you must enter this code before every fight. Also this is an unlockable cheat. It will be displayed if you beat the game on V.HIGH difficulty using less than 6 continues during the game.
Source: gamefaqs.com

(UNI) Arena select (added 08.08.18):
This cheat works only for 2-players mode only (either via game link or in SGB mode). At the versus screen, hold Up or Down and press one of the control buttons to play a particular arena rather than assigned to the opponent. Full list of combinations in the table below. Note, the Eyedol arena inaccessible with this cheat. Also note, the Secret Arena is a special hidden arena for 2-player mode only and can be accessed only via this cheat.
Hold|Press|Arena
Down|A|Arena Orchid
Down|B|Arena Jago
Down|Select|Arena Combo
Down|Start|Arena Fulgore
Up|A|Arena Glacius
Up|B|Arena Sabrewulf
Up|Select|Arena Thunder
Up|Start|Arena Spinal
Up + Left|Select|Secret Arena

King of Fighters '95, The (USA), Nettou The King of Fighters '95 (Japan)

(GEN) Frame advance mode (added 10.08.18):
Pause the game with Start, then press Select to advance the game frame by frame. To return to normal game preaa Start again.
Source: gamefaqs.com

(FIX) DIP switches (added 10.08.18):
There are a set of internal game flags called "DIP SW(itches)". Each flag, when set, enable one of corresponding features. To set any of these flags, at TAKARA logo enter particular button combination from the table below to get a corresponding effect. Every time one of the flags set, the corresponding sound will be heard. Note, some of features available only in Super Game Boy mode. To see what DIP switches are enabled, go to options screen. At the bottom of the screen there will be string "DIPSW-XX", where XX is a hexadecimal sum of all enabled DIP switch bits.
SGB only|Code|DIP SW|Effect
No|Hold A + B, press Select 1 time.|bit 5
(HEX 20)
|Allow to select all the same characters in the "TEAM" game mode for one team.
No|Press Select 3 times.|bit 6
(HEX 40)
|Unlocks Saisyu and Rugal extra characters. Also these characters may be unlocked if you complete the game on "NORMAL" mode.
No|Press Select 20 times.|bit 7
(HEX 80)
|Unlocks Nakoruru extra character. Also this character may be unlocked if you beat the game on "HARD" mode.
Yes|Press Select 25 times.|bit 3
(HEX 08)
|Activates infinite "MAXIMUM" gauge meter for both players.
Yes|Hold A + B + Left, press Select 30 times.|bits 2,4
(HEX 14)
|Enables the SGB Sound test mode at options menu. Also enables two special move shortcuts. During the game, press either Select + B or Select + A to perform one of two most powerful moves for a corresponding character.
Note, that because of specific of the code input and check method, all button presses counted at the same time, so if you entering one of the codes, you already entering all others. So if you just quickly press Select at least 25 times at least three codes enables at once. To unlock all flags at once, first, hold A + B, press Select once, while still holding those buttons, hold additionally Left, then press Select very quickly 30 times. When you hear a final explosion sound means all codes are activated.
Source: gamefaqs.com

(UNI) Auto play (added 10.08.18):
At the "GAME SELECT" menu, chose any option, then hold B and press A. As the "PLAYER SELECT" screen now you may select CPU controlled fighter for your side. Note, this does not mean your CPU controlled fighter will WIN all the time.

King of Fighters, The - Heat of Battle (Europe), Nettou The King of Fighters '96 (Japan), Nettou The King of Fighters '97 (Pirate), King of Fighters '98, The (Pirate)

(GEN) Frame advance mode (added 11.08.18):
Pause the game with Start, then press Select to advance the game frame by frame. To return to normal game preaa Start again.
Source: gamefaqs.com

(FIX) DIP switches (added 10.08.18):
Since this game shares mostly the same engine with King of Fighters '95, the same "DIP SW" flags are accessible here also. All coding and behaviours mostly the same except some different effects described in the table below. Also as against the previous version, this one allows to enter all cheats no matter if they may work in SGB mode only.
Code|DIP SW|Effect
Hold A + B, press Select 1 time.|bits 5,3
(HEX 28)
|Allow to select all the same characters in the "TEAM" game mode for one team. Also changes the POW GAUGE meter behaviour. Now it will constantly increase during the fight, no matter if you get hit or not. Also in will increase faster in some special cases.
Press Select 3 times.|bit 6
(HEX 40)
|Unlocks Goenitz extra character. This code is unlockable and given to you if you beat the game on "NORMAL" mode.
Press Select 20 times.|bit 7
(HEX 80)
|Unlocks Mr.Karate extra character. Also this enables a different characters selection for Iori, Leona and Chizuru. During player selection, press Start on these characters to change them to Iori', Leona' and Kugara correspondingly. This code is unlockable and given to you if you beat the game on "HARD" mode. Additionally this changes the default SGB border to a little bit different one.
Hold A + B + Left, press Select 30 times.|bits 2,4
(HEX 14)
|If you run this game in SGB mode it will enable the SGB Sound test at options menu. In all other modes this enables two special move shortcuts. During the game, press either Select + B or Select + A to perform one of two most powerful moves for a corresponding character.
Note, all codes may be activated at once the same way as for King of Fighters '95, see above.Source: gamefaqs.com

(UNI) Auto play (added 10.08.18):
At the "GAME SELECT" menu, chose any option, then hold B and press A. As the "PLAYER SELECT" screen now you may select CPU controlled fighter for your side. Note, this does not mean your CPU controlled fighter will WIN all the time. This cheat not available in the Game Boy Link mode, but can be used in the SGB mode.

Kingyo Chuuihou! - Wapiko no Wakuwaku Stamp Rally!

(BUR) Game genie (added 13.08.18):
001‑7CE‑C4D-Re-enables debug leftover. Press Start any time during the game to cycle through entire set of screens, mini-games and other game routines.

Kinin Koumaroku Oni

(BUR) Hidden text (added 13.08.18):
The WRAM initialization routine uses as a signature word:
WINKY


Kirby's Block Ball (USA), Kirby no Block Ball (Japan)

(BUR) Game genie (added 14.08.18):
512‑8FE‑C43 (for the US version)
512‑6EE‑C43 (for the Japanese version)
-Enables the access to Debug menu via Soft reset code (A + B + Select + Start) any time during the game. Debug menu allows you to start to play from any regular or boss stages, play all bonus games on any difficulty level, watch various game animations and all endings.
Source: tcrf.net

Kirby's Dream Land (USA), Hoshi no Kirby (Japan)

(GEN) Title screen cheats (added 14.08.18):
At the title screen, press one of the following button combinations at the same time to get the corresponding effect.
Down + Select + B-Configuration screen and Sound test.
Up + Select + A-"Extra game". Harder game mode with different sets of graphics for enemies.

Kirby's Pinball Land (USA), Kirby no Pinball (Japan)

(GEN) Ranking clear (added 15.08.18):
At the Ranking screen, press Down + Select + Start at the same time.
Source: urawaza.in

(FIX) Title screen cheats (added 15.08.18):
At the title screen, hold Select along with one of the buttons described below and press either A or B to get a corresponding effect. If done right, the title screen switches to a Ranking screen and a small cat character will walk on the floor. Now return to the title screen with A or B and start a new game.
Button|A Cat|Effect
Left|A white cat walk right to left.|Bonus games only mode.
Right|A black cat walk left to right.|Boss games only mode.
Source: gamefaqs.com

Kirby's Star Stacker (USA), Kirby no Kirakira Kids (Japan)

(GEN) Sound test and mini-games (added 15.08.18):
The extra options are unlocked after completing the game to 100%. Just go to the game loading screen and select your 100% save file. You may choose now to play two bonus mini-games or access the Sound test.
Source: gamefaqs.com

Kitchen Panic

(UNI) Stage select (added 15.08.18):
At the title screen, hold Down + Left, then press Start.

(BUR) Hidden text (added 15.08.18):
There is a hidden copyrights at the beginning of the ROM:
1991-2-22
and
programmed by Motos.Kanayama

Source: tcrf.net

Kiteretsu Daihyakka - Bouken Ooedo Juraki

(FIX) Title screen cheats (added 16.08.18):
All cheats entered at the title screen. Only one cheat may be entered at once. For three credits screen cheats the final Select button need to be pressed and then held for a couple of seconds until cheat is triggered.
Up, Down-No cutscenes.
Left, Left, Right, Right, Up, Down, A, B-Stage select.
Source: makainyumon.web.fc2.com
Left, Left, Right, Right, Up, Down, A, A-Invulnerability.
Source: makainyumon.web.fc2.com
Left, Left, Right, Right, Up, Down, A, A, B-Stage select and Invulnerability.
Source: makainyumon.web.fc2.com
Up, Left, Down, Right, Up, Left, Down, Right, B, A-Sound test.
Source: makainyumon.web.fc2.com
B, B, B, B, B, A, B, B, B, B, B, Select-Director credits screen.
Source: makainyumon.web.fc2.com
A, A, A, A, A, B, A, A, A, A, A, Select-Character designed credits screen.
Source: makainyumon.web.fc2.com
A, B, Right, Left, Right, Left, Down, Down, Up, Up, Select-Programmer credits screen.
Source: makainyumon.web.fc2.com
Up, Right, Down, Left-Mini games test.
A, B, B, A-Cutscenes viewer.

Kizuchi da Quiz da Gen-san da!

(BUR) Game genie (added 18.10.17):
992‑979‑B31-Re-enables the location skip at the Map screen. Press either A, B or Select to skip to the next location. Press Start to play at current location.

Klax (Japan, Hudson Soft)

(GEN) Debug leftover (added 16.08.18):
Any time during the game, press Select to instantly obtain a specific block on the paddle. It seems this is a debug leftover that developers forgot to remove.
Source: gamefaqs.com

(UNI) Any Wave select (added 16.08.18):
At the Wave select screen, press Up, Up, Down, Down, Up, Down, Up, Down, Up, Up, Down, Down. The screen changes to a new Wave select mode where you may select any wave from 001 to 100.

Koi Wa Kakehiki

(GEN) Special start stage (added 16.08.18):
At the title screen, press Down, Up, Right, Left, B. In case you beat this very hard stage the message "LOVE AND PEACE" will appear.
Source: urawaza.in

Koro Dice

(FIX) Secret passwords (added 17.08.18):
Start a new game, choose mode and any level above 3 to be able to input password. Input one of the following passwords to get a corresponding effect.
49551-Sound test.
Source: gamefaqs.com
61283-1P lvl 10 cutscene
19792-1P lvl 20 cutscene
25761-1P lvl 30 cutscene
67373-1P lvl 40 cutscene
19923-1P final cutscene
97374-VS win 1
39672-VS defeat 1
66422-VS win 2
33011-VS defeat 2

Kung-Fu Master (USA), Spartan X (Japan)

All versions:

(FIX) Hidden text (added 18.08.18):
The RAM initialization routine uses this word as a signature at RAM location $FF9E:
HIRO


Japanese version:

(FIX) Sound test (added 07.01.17):
At the difficulty selection screen, hold B, then press A.
Source: tcrf.net

(UNI) Stage select (added 07.01.17):
At the difficulty selection screen, hold Left, then press A 5 times, release Left, then hold Right and press B 3 times, release Right.

Kuusou Kagaku Sekai Gulliver Boy - Kuusou Kagaku Puzzle Purittopon!!

(FIX) Stage select (added 19.08.18):
At the title screen, hold Up, then press A 12 times. A sound will confirm correct code entry. For Story mode, pause the game, press Select to cycle between levels 01 to 14, unpause it to just right to this level. Also, on pause press Down + A + B at the same time, then unpause to instantly complete current stage. For Puzzle mode, the only Stage select code works the same way, but levels from 01 to 50 are available.
Source: urawaza.in

Kwirk (USA, Europe), Puzzle Boy (Japan)

(UNI) Linear course (added 10.05.16):
In the "Heading out" mode, the room course is random and rooms selection depends only on the skill level. But, if at the "Select display" screen you hold Left + Select before startin a game, the course will be always the same with linear room arrangement, but you can't select a number of rooms to play, it is fixed too and depends also on the skill level only.

Lamborghini American Challenge

(UNI) All stages and 999999 money (added 20.08.18):
There are no secret passwords in a usual manner in this game. So no specific sequences of letters to input as a passwords here. However, go to the password screen, put cursor to the rightmost letter and set it to "F", then hold Select + B and press Up. Instead of wrapping back to "0" the letter increased past "F", to "G". Release all buttons. Now pressing Up increases this letter up to "Z". Set it to "X" and press either A or B. Such "password" accepted with a specific sound, and game started with all stages unlocked and with $999999 money.

Lawnmower Man, The (Europe), Virtual Wars (Japan)

(UNI) Easter egg (added 20.08.18):
Wait at the title screen until the animation sequences begins. At the second animation sequence with "LAWNMOWER" zooming out, hold A + B + Up. While holding these buttons press Left/Right to manually zoom the message. To return back to normal animation, just release all the buttons.

(UNI) Cheat menu (added 20.08.18):
Before powering the console, hold A + Right. Power up the console, when license screen appears release these buttons and hold B + Left, then press Start or just wait for the intro begins. Wait for intro is over or just skip it. If all done correctly, the "(c)" symbol in "(c)1993" string at the title screen turns into black smiling symbol. Now, hold A + B + Down and press Start. The menu with version number/date and header "BLUE MEANIE MODE!" will appear. This menu allows you to play any game level including vitual worlds, also disable virtual words or enable infinite lives.

(BUR) Hidden text (added 20.08.18):
There is a hidden copyright and version/date text at the very beginning of the ROM. For the Japanese version text is:
THE LAWNMOWER MAN JAP v1.90 01/11/93 BY KEN MURFITT.
For the European version:
THE LAWNMOWER MAN EUR v1.95 11/11/93 BY KEN MURFITT.

Source: tcrf.net

Legend of Zelda, The - Link's Awakening (USA, Europe), Zelda no Densetsu - Yume o Miru Shima (Japan)

(GEN) Secret names (added 12.03.18):
Enter one of these words as a Player's name at the beginning of a new game to hear the different background music on the Save selection screen. Different game versions uses a different words and a different set of music.
ぜるだ (for the Japanese version)
ZELDA (for the Western versions)
-Title screen remix.
とたけけ (for the Japanese version only)-Totaka's song.
MOYSE (for the German version only)-Moyse's song.
LOLO (for the French version only)-"Lolo" song.
Source: tcrf.net

(BUR) Game genie (added 12.03.18):
010‑03F‑E6A-Re-enables first portion of debug leftovers sitting in the game. When enabled there are several featurea available during the game:
At the game boot, slot 1 save will be overwritten with precomposed save state with name ZELDA and maxed out parameters, as well as unlocked all grotto levels.
Any time during the game, hold any D-Pad button then press Select to hold the game. Press Select to unhold the game. Also every time you exit the hold state, a Free Walk mode toggles on and off.
At the map screen, press Select + B to warp in the center of currently highlighted area. This also disables the ability to exith the Map screen with B.
When Player's name starting with 1 zero character (which normally impossible), the Marin object turns to Message debug object. Use D-Pad to change current index, press A to see bank 0 messages, and B or Select to see bank 1 and 2 messages respectively.When Player's name starting with 2 zero characters, the Marin object will immediately start the Ending sequence.
Source: tcrf.net
010‑04F‑E6A-Re-enables the second portion of debugging features. For some debugging reasons, this flag disables a couple of redrawing routines. The different regional versions has a different sets of disabled routines. For example, there are no items redraw on the items screen (as well as equipped items) and entry arrows on the mini-map in the US version.
The main feature for this flag is ability to control the Ending sequence. Press Left/Right to skip to the next scene, press Down/Up to start the Ending sequence from the beginning.
Source: tcrf.net
282‑B5A‑80A (for all versions)-Re-enables an additional debug leftover, not using the debug flags mentioned above. Any time during the game, hold B then press Select to warp instantly to grotto level at some fixed position. Also draws a full map of the grotto but without chests. There are 11 hard coded locations in a table associated with this debug leftover. After 11th location code wraps back to the first one. Note, this feature uses the same button combination as map warping feature so both debug features can't be used at the same time.

Legend of the River King GB (USA, Europe), Kawa no Nushi Tsuri 3 (Japan)

(BUR) Game genie (added 16.10.17):
003‑55E‑7F6 (for the US version)
003‑32E‑7F6 (for the Japanese version)
-Re-enables the Debug menu activation code. Any time during the game hold A + B and press Select.
In the US version they swapped Select and Start for in-game mode. This changes the Debug menu activation code in this mode as well, you need to press Start instead of Select.
Although the US version version has all the same debugging functions working, there is no proper font loaded as well as the text resources are lost during translation.
The debug mode allows you to jump directly to any system game handlers or sub-handlers (where debug has index $07), also setup the map index, current location, strength, money and experience.
Two "DUMMY" and one "DEBUG" parameters aren't used in the release version.
001‑DCA‑C4D (for the US version)
001‑C2A‑C4D (for the Japanese version)
-In the release version, you can see the float as a small object in the river only. With this code enabled, there is a closeup picture of the float will be displayed. However, the catch animation resourses are unused here so seems they removed it on early stage. Since the closeup picture is a sprite it interferes with other sprites and can make fish or float invisible or overlapped with it.

Lemmings

(BUR) Game genie (added 22.08.18):
CDA‑97E‑919 (for the US version)
CDA‑92E‑919 (for the Japanese version)
CDA‑83E‑919 (for the European version)
-Demonstrates how the debug assert routine looks like in this game. The program still performs some assertion checks to show this but obviously all code well debugged and never goes to this crash handler.
Source: tcrf.net

(BUR) Hidden text (added 22.08.18):
There is a hidden text line in ROM used to mark the end of the program part of the game. All data after first entry of this line is a garbage (may even contain this line itself):
THE END IS NEAR


Lemmings 2 - The Tribes

(BUR) Hidden text (added 22.08.18):
There is a hidden copyright scring at the beginning of the ROM:
Copyright SPIDERSOFT 1994

Source: tcrf.net

Les Aventures De TinTin - Le Temple du Soleil (Tintin - Prisoners of the Sun)

(UNI) Sound test (added 22.08.18):
At the title screen, put cursor to "START" option, hold Up and press A or Start.

(UNI) License screen cheats (added 22.08.18):
At the license screen, enter one of the following cheats to get the corresponding effects. Note, sequences may be entered only in a particular order. You cannot input sequence 2 first, only after sequence 1 and so on. Every time sequence succesfully entered a sound will be heard.
Sequence 1: B, A, Up, Down, Right, Down, A-During pause, press Select to advance the game frame by frame. Press A + B to enter the Stage select mode. Note, you can jump only to a beginning of every level. Sublevels are not available in this Stage select.
Sequence 2: Up, Down, A, B, Down-Additionally enables invulnerability and infinite lives for places where invulnerability does not work.
Sequence 3: B 28 times, then A.-Although this cheat may be entered, it seems does nothing. Can't see any code that check for this third cheat, but maybe they used some optimized code portions with partial offsets, need to investigate more then.

(BUR) Hidden text (added 22.08.18):
There are few leftover text in the sound engine bank. First is the single source line for some portion of the sound engine obviously with comment in spanish:
	JR	Z,$SOLO1	; Solo necesita la primera envol
The second string is a end of data/code mark for the sound engine. All bytes past this string is an unused space.
Final de la rutina de musica

Source: tcrf.net

Lethal Weapon

(GEN) Cheat mode (added 23.08.18):
At the title screen, press Down, Up, Left, Left, Up, Right. A sound and a message "CHEAT MODE" confirms correct code entry. This gives you infinite health and ammo.
Source: gamefaqs.com

(BUR) Hidden text (added 23.08.18):
There is a hidden copyright string at the beginning of ROM:
PROGRAMMED BY TIM COUPE (C) 1992 EUROCOM DEVELOPMENTS
Also, worth nothing, but the random generator initialized in this game with string:
TIM!

Source: tcrf.net

Lion King, The

(GEN) Pause cheats (added 23.08.18):
Pause the game with Select then enter one of these cheats.
B, A, A, B, A, A-Stage skip.
B, A, A, Left-Suicide.
Source: gamefaqs.com

(BUR) Hidden text (added 23.08.18):
There is a hidden bible quotation inside the ROM similar to text used in the NES version of the same game by the same developer:
Suffer little children to come unto me


Little Indian (An Indian in the City, Un Indien Dans La Ville)

(GEN) Stage skip (added 24.08.18):
During the game, pause it with Start, then press Right, Right, Right, Right, Down, Down, Down, Left, Left, Up. A sound confirm correct code entry. Now any time on pause, press Select to skip current stage. However, after the last stage this code will wrap back to the very first stage.
Source: gamefaqs.com

Little Master 2 - Raikou no Kishi

(GEN) Secret world menu (added 25.08.18):
In order to access this menu you must complete game for the first time. Return to the title screen and at "PRESS START" message enter Up, Up, Down, Down, Left, Right, Left, Right. An additional menu option "ひみつのせかい いりぐち" ("Entrance to Secret World") will appear above the "PUSH START" message. Now press one of the buttons described in table below to get a corresponding effect.
A-Sound test.
B-Battle backgrounds test.
Select-Ending characters presentation.
Start-Enemy test.
Down-Story cutscene animation 1.
Up-Story cutscene animation 2.
Left-Ending cutscene animation.
Right-Return to the title screen.
Source: urawaza.in

Little Mermaid, The

(UNI) Invulnerability (added 27.08.18):
Hold A + B + Select before powering the console on. If done right, Mermaid turns completely invulnerable.

Lock 'N Chase

(GEN) Title screen cheats (added 27.08.18):
At the title screen, when "START" is displayed, enter one of the following sequences to get a corresponding effect.
A, A, B, B, A, B, B-Extra stages. This code is unlockable and given to you after beating first 18 stages.
A, B, Up, Up, Down, Down, A-Start on Stage 2-1.
A, B, Right, Right, Left, Left, A-Start on Stage 3-1.
A, B, Down, Down, Up, Up, A-Start on Stage 4-1.
A, B, Left, Left, Right, Right, A-Start on Stage 5-1.
A, B, Up, Down, Left, Right, A-Start on Stage 6-1.
Source: gamefaqs.com

Looney Tunes (USA), Looney Tunes - Bugs Bunny to Yukai na Nakama-tachi (Japan)

(GEN) Extra 7 lives (added 28.08.18):
At the title screen, press A, B, B, A, Select, Select. A sound confirms correct code entry.
Source: gamefaqs.com

(UNI) Restore HP (added 28.08.18):
During the game, pause it with Start, then press A + B + Select to restore HP. This may be done only once per level.

Lost World, The - Jurassic Park (USA), Monde Perdu, Le - Jurassic Park (France)

(GEN) Title screen cheats (added 28.08.18):
At the title screen, press one of the following codes to get a corresponding effect. Also you can activate more than one code at once.
Up, Down, B, B, A-Replaces Password screen with Stage select screen.
Select, Up, Up, Select, Down, Down-Infinite ammo.
Left, A, Up, Right, A, Down-infinite health.
Source: gamefaqs.com

(BUR) Game genie (added 28.08.18):
0A1‑E8F‑E6A-Replace the title screen with an unused Cutscenes viewer. Note, "LABS EXPLODE" crashes the game. Also there are no ending cutscenes in the list. Also worth nothing, but there is an unused cheat sequence between the used ones at 0x00819F in the ROM (Select, A, Down, B, Up, Down), which may be intended to access this particular viewer.
Source: gamefaqs.com
775‑12F‑3BB+C2A‑A4E‑C41-Re-enables the Memory viewer/Crash handler. Start the new game it wil appear as soon as level starts.

Lucky Luke

(FIX) Stage skip and Restore HP (added 28.08.18):
At the title screen, press Down, Up, Down, Up, Left, Right, Left, Right. A sound confirms correct code entry. During the game, press Start to instantly restore HP or press A + B + Select to skip current level.
Source: gamefaqs.com

Lucle

(GEN) Options menu (added 20.02.17):
At the title screen, enter Up, Down, Left, Right, A, B, B, A, B, A, B, A, A. The palette on the "L" letter in title inverting indicating correct code input. Now start a new game.
Source: makainyumon.web.fc2.com

(BUR) Hidden text (added 20.02.17):
The SRAM init signature in this game contains some devs credits:
KOJI-YOSIDA 5963


Mach Go Go Go

(UNI) Secret car (added 30.08.18):
Start a new game, at the "MACHINE SELECT" screen, put cursor to "MACH" (top-left character), then press Right, Up, Up, Left, Down, Down, Select. A new machine "ALBATROS" will appear instead of "MACH". This machine has best acceleration out of all cars: 10.

(UNI) Secret passwords (added 31.08.18):
Complete the game once to activate the "PASSWORD" menu option at the title screen. Since that game uses CRAM saves to keep current game data, this password screen is used only for input a secret passwords which never told you by the game itself. Not sure where you were able to find these passwords, but it seems they may spread over some magazines later. Note, the secret car also has a full set of corresponding passwords.
Effect|WAGP|Mach|Stinger|Cutthroat|Red Papillon|Shooter's Arrow|Warp|Albatross
Regular items: default
Special items: all (except "Gallant" for cars other than Mach and "Mirage Shoot" for all)
Stats: default
|Yes|SEFETYSEVEN|LOUNISYGRET|BIUYDKOUSJY|MOISJUDTEGY|JUTRBUYGCDA|LPOBTDIUJRS|QHUYARSPLUD
Regular items: default
Special items: "Mirage Shoot"
Stats: default
|No|BIUSYHDREPL|NOKUSHIDYGR|YGSLODHGRAU|ZGSOIDKUFBT|RBLOSUJDIYG|HGGSIUAYWTB|CISKJDTFEPI
Regular items: all
Special items: all (except "Mirage Shoot" for all)
Stats: default
|Yes|TGOILSNZUKP|PSIYEUIBSAM|IUAHDYFSALM|NSIHDYEJOSA|MODUYHFIYAT|YEUTDNBPSAI|MALSDJNSALJ
Regular items: default
Special items: default
Stats: 30 PW/SP/AC/DE/HP
|No|NJLDCMSALNP|TETFAKSSKHA|REFDLSMJCKJ|LMKLDVSDLDL|PSJDHACSMJH|WASBKSDLKMD|TGEVDJKBVKS
Regular items: default
Special items: default
Stats: 50 PW/SP/AC/DE/HP
|No|SJDJVHBKLSD|KAVAJHXLDMC|KLDJVJNCLML|PWJDXEVDHXD|DFQWXBKNXML|PUDCUGJHSWL|BHSUYDRTAMO
Regular items: default
Special items: default
Stats: 70 PW/SP/AC/DE/HP
|No|XSTGDUFJYRT|VYSGFDIUYFY|BSHUDTHODFY|NDSOIUDOASN|KDHGGSJDLSD|KSHFAFSVZMU|LOSFDJHYFUJ
Regular items: all
Special items:
for Mach: "Mirage Shoot".
for all others: all (except "Mirage Shoot")
Stats: default
|No for Mach
Yes for all others
|BKCKUSYTJDF|EWKDXKHDYBI|BDKSNLSHGUI|FRYDIHKSYSU|PLOIUKUSJGY|GOUANKZNSAH|DJCJGNSXLSM
Show ending|-|GOUHIBIKIEN|JETSONENDIN|MIKAELENDIN|SECILENDING|XRESAENDING|AKIHABARAEN|NKJDOUAHTDU

(BUR) Game genie (added 30.08.18):
071‑64F‑E6A-Re-enables the unused and seems unfinished "DEBUG MODE" screen. Only "STAGE" work here. "MUSIC" is only a text on the screen.
Source: tcrf.net

Madden '95

(BUR) Game genie (added 03.09.18):
051‑93F‑E62+CF1‑9AF‑081+761‑9BF‑083-Re-enables an unused "SOUND EFFECTS MENU". There is another string for another menu "MUSIC MENU" but no one access it.

Madden '96

(FIX) Extra teams (added 04.09.18):
When selecting teams in "EXHIBITION" mode, choose "ALL MADDEN" team, hold Select + B then press Right once to select first extra team "TEAM HALESTORM". At this team, while still hold Select + B, press Right one more time to select second extra team "DA FUNHOUSE".
Source: gamefaqs.com

(UNI) Extra game length (added 04.09.18):
When selecting the game length in any game mode, choose "60 MINUTES", hold Select + B then press Right to set game length to "4.0 MINUTES".

(UNI) Instant scores (added 04.09.18):
In any game mode, at the pre-game menu, put cursor to "START GAME" option, hold either Select or B then press A. According to button held either the Home or Visitor team will start the game with 190 points correspondingly.

(UNI) Game skip (added 04.09.18):
At the screen before the pre-game menu where you choose one of two selected teams to play, hold Down then while holding it do the Instant scores cheat. The current game will be skipped instantly with team which you gave Instant scores as a winner. You may not only skip and win any playoffs or season games, but also exibition or even demo games (if hold Select or B with Down and just wait for demo starts). However this is pointless.

(UNI) Instant coin toss (added 05.09.18):
At the coin toss screen, choose one of two sides then quick hold Select + B and wait the result which now will always be the same you selected rather than randomized.

(BUR) Game genie (added 04.09.18):
004‑0FF‑F7E-There is a working crash handler in this game. When triggered during the game in GB mode, it starting to change palette in a dead loop causing the specific screen effect. When played in SGB mode, it displays two information screens with current game statistics, then jumps to the "INSTANT REPLAY" mode. When exit from it, goes to the same palette lock up as in GB only mode.
Source: tcrf.net
803‑D78‑809-Replaces the "START GAME" menu option of any game mode with "SOUND EFFECTS MENU". It seems this is some kind of leftover from the previous part of the game. The screen is not initialized properly which causes some graphical glitches, as well as actual sound play commands are disabled and you only able to change menu items.
A14‑8B8‑C44-Replaces "INSTANT REPLAY" option of "EXHIBITION" game mode with its debug version, which works mostly the same (scroll cursor throught the play field, point to any player to see the info about it), but instead of replaying the currently played game from the beginning, it used to play current game frame by frame when Select pressed.

Magic Ball (Unlicensed)

(BUR) Hidden text (added 06.09.18):
There is a hidden copyrights string at the beginning of the ROM:
GOWIN MAGIC BALL 930920
There may be more Shift-JIS encoded text near, investigate.

(BUR) Game genie (added 06.09.18):
6E7‑97B‑917-Re-enable a hidden Level editor. It is very plain simple and buggy. There is also an unused string "EDIT" in the text data set.

Magical Taruruuto-kun

(GEN) Sound test (added 06.09.18):
At the title screen, press Select, a Taruruto character will disappear from the screen. Select sounds/music with A/B, press Start to play them at once.
Source: urawaza.in

(BUR) Game genie (added 06.09.18):
010‑07F‑E6A-Re-enable debug features. At the title screen hold one of following buttons and press Start to get to the corresponding stage:
Right-Stage 2
Down-Stage 3
Left-Stage 4
During the game, press Start then one of the following buttons to get a corresponding effect:
Up-Increment lives.
Down-Toggle invulnerability on and off.
Left-Toggle free walk mode on and off.

Magical Taruruuto-kun 2 - Raibaa Zone Panic!!

(UNI) Instant items (added 07.09.18):
During the game, press Start to pause it. Press Left, B, B, Right, Select, then one of the following buttons to obtain one of items instantly. This is only works if no items already taken. There are no indication on HUD what item is taken, only wear its effect. As against the regular items, items obtained with this method has no expiration period, they only be removed when stage is complete/loose or when any other regular item were taken.
Up-"Shoes" item. Gives high jump and faster walking speed.
Down-"Tongue" item. Literally enlarge your tongue.
Left-"Poo" item. Grants you invulnerability, but also disables ability to eat buns.
Right-"Pie" item. Slow down all enemies.

Magnetic Soccer

(UNI) Sound test (added 07.09.18):
Any time during the game except the title screen, press A + B + Select + Start to perform a Soft reset. Quickly, while screen fades, press Up + Right.

(UNI) Skip to P.K. (added 07.09.18):
Start a new game either in 1p or 2p modes, complete game setup, but at the last option ("COM LEVEL" for 1p mode, "SET" in 2p mode), press A + Start at the same time. The game will over immediately with score 0-0, so P.K. series begins.

Mahou Kishi Rayearth (Magical Knight Rayearth)

(GEN) Sound test (added 08.09.18):
At the title screen, press Select 32 times.
Source: urawazagame.com

(BUR) Game genie (added 08.09.18):
498‑A3C‑19A-Replaces in-game Save menu with a complex Debug menu. You can Load from it, change walking speed, enable or disable debug output/free walk/random encounters, jump to any map and also listen to all music/sound effects and a PCM voices for currently selected character.

Mahou Kishi Rayearth (Magical Knight Rayearth) 2nd - The Missing Colors

(UNI) Sound test (added 10.09.18):
At the title screen, press B 32 times.

Makaimura Gaiden - The Demon Darkness

(BUR) Game genie (added 11.09.18):
BF0‑68F‑E6A+0F0‑30C‑D5A-Each bit of the byte at ROM offset $000068 is a debug flag. First code set most of them at once except one that disables the action stages HUD. Another code replaces the Soft reset button combination (Select + Start) also activated by the debug flags, with regular one (A + B + Select + Start) to not to interfer with Sound test feature. Some features are enabled via holding a particular button on the title screen before starting the game with Start. These buttons may be combined to enable more than one effects at the same time.
Feature|Title button|Notes
Sound test|Select|Appears after the title screen immediately.
Stage select|B|Appears after starting a new game. Note, Stage 00 is a debug stage, not used in the game.
Invulnerability|Down|Works on the action stages against any enemies or harmless obstacles like spikes.
Debug output|A|Activates after switching the maps at the bottom part of the screen, which also replaces HUD in the action stages.
Action mode menu debug|Always on|During action stages, press Start to enter the items menu.
Press Select to get all items.
Press A to increase "J" (jump height).
Press B to increase "W" (flight stamina).
Free walk|Always on|During either overworld or action stages, hold A, press Select to toggle Free walk mode on and off. Use D-Pad to move character to any part of the screen.

Mario's Picross (USA, Europe), Mario no Picross (Japan)

(FIX) CRAM clear (added 14.09.18):
To erase an individual save slot, at the "DATA SELECT" screen, put cursor to slot to be erased and hold A + B + Select for a while, then press A when game ask to erase or not. To erase all saved data at once, before powering the console, hold Up + Left + Select then power it up. Game will ask to erase save data or not. Press corresponding button to agree or decline. Note, both codes are described in the original english instruction manual for this game. However, the all erase code there is incorrect, it claims that button code is Left + Select.
Source: gamefaqs.com

(GEN) SGB extra border palettes (added 14.09.18):
In SGB mode, at the title screen, hold one of following buttons and press A or Start to change default border color (Green) to one of four extra colors:
Up-Black
Down-White
Left-Yellow
Right-Red
Source: gamefaqs.com

(BUR) Hidden text (added 14.09.18):
The game uses following name as part of the internal RAM signature:
Noriaki Teramoto
Also the sound engine bank contains copyrights of the composer:
DSEQ
APE (C) mcmxciv by Toshiyuki Ueno
pcs26448@asciinet.or.jp

Source: tcrf.net

Marmalade Boy

(UNI) Secret passwords (added 15.09.18):
キミワ カシコイ
・・・ ・・・・
-Literally translated as "You Smart". Jumps directly to ending with making staff sequence.

Masakari Densetsu - Kintarou Action Hen

(GEN) Secret passwords (added 15.09.18):
はちのすほしい!!!!-Start the game with extra 20 honeycombs.
おつかあのたすけ!!!-Debug mode. Press Start to advance to selected level. Press Select to switch to Cutscene view select mode. Select with A/B in all modes.
Source: makainyumon.web.fc2.com

Masakari Densetsu - Kintarou RPG Hen

(FIX) Debug mode (added 17.09.18):
Before powering on the console, hold A + B + Select + Down to enable debug letovers the developers forgot to remove. During the game:
The main game menu now have two extra options "SAVE" and "LOAD".
Hold B to free walk throught obstacles.
Press Start to toggle random encounters off and on. Also when in battle, you will always win.
Hold A, press Start to open simple party editor. There are a lot of values of all 4 party members and its stats.
Hold B, press Start to open simple memory watch. There are no proper font letters for hexadecimal numbers though.
Hold Select, then press Start to instantly erase save data without any confirmation. Note, the B button used normally to open ingame menu when character is not moving, but when menu is open debug codes does not work. So you need either, to hold B button while move or press B once to open menu first then press and hold it to close menu, in order to use debug features.
Source: makainyumon.web.fc2.com

Maus, Die

(UNI) Stage select:
At the license screen, quiclky enter A, B, Up, Down, Down, A, Left. During the game, on pause, hold A + B and change the level number with D-Pad buttons, then unpause. Or just hold A + B and unpause to skip to the next level.

(UNI) Infinite lives:
At the license screen, enter Up, Left, Right, Down, Left, Up, Right, Up, Down, Right, Up, Right, Down, Left, Left, Down, Right.

(UNI) Secret message:
At the license screen, enter Up, Left, Down, Left, Up, Right, Down, Up, Right, Up, Right, Down, Left, Up, Down, Right, Down, Up, Down, Up, Right, Up, Left, Up, Right. Complete the game (you can use the Stage select cheat as well). After the credits roll is over, hold Up + Right + B, then press Start. The dedication screen will appear, the same as in some other Bit Manager's games.

Max (USA, Europe), Rubble Saver II (Japan)

(GEN) Extra life (added 17.09.18):
Start a game, begin to play STAGE 3. Go down to the bottom of the level. In leftmost part of the floor there is a statue on a hill. Shoot this statue from the right side, then from the left side, repeat the same one more time, then shoot one more time from any side to obtain an extra life. This can be done only once per game.
Source: makainyumon.web.fc2.com

Medarot (Kabuto, Kuwagata, Parts Collection 1 and 2 versions)

(GEN) Options mode (added 07.10.18):
At the title screen, hold Select then press A or Start to enter the menu whete you can listen to the music and sounds and chose to clear the save data as well.
Source: urawaza.in

(UNI) Medal levels view (added 11.10.18):
At the title screen, press Up, Left, Down, Right, Up, Down, Left, Right, Select. Now during the game, when you able to access the in-game menu with B, go to first menu option "ケイタイ", then "メダル" ("Medal"). Choose any medal, then at the medal info menu press Left to change current medal level (up to maximum 12). Note, this will only display the possible levels of current medal and its appearance, you cannot keep selected level so this cheat hardly useful enough.

(UNI) Disable random encounters (added 11.10.18):
At the main menu, go to configuration mode, press Select, Select, Select, Select, Select, Up, Down, Left, Right, Start. This disables the random encounters during the game.

(BUR) Debug leftovers (added 11.10.18):
There are few debug leftovers still in the game barely working. Since there is no more code to acces all these features inside the game, you can only access it by modify the main/sub system routine indexes at $C5C0/$C501 runtime. Here is a table with available values.
$C5C0|$C5C1|Effect|Notes
$06|$0B|The debug menu.|You can select story, event number and level. These values are applied as current scenario position and world triggers and NPC states are changes according to it. Need to mention, $06 mode is for ingame, so you don't need to set it manually, but start a new game instead.
$0B|$00|VRAM/Sound test|At start, there are three screen will be displayed with currently loaded tile data, skip them with A button. The last screen will display the Sound test menu, however, since there are no proper font loading here, you may see the garbage unless you access this screen after the debug screen described below.
$0C|$00|Map test|This screen does load a proper font to display some kind of menu leftover. There is only one option is active selecting any game map to start with. Sometimes this may cause heavy glitches. You may access this menu also during the game by using the Game Genie code 0C3-B6B-B3A, then just do the generic "Sount test and CRAM clear" cheat at the title screen.
Source: tcrf.net

MegaMemory v1.0 by Interact

(GEN) Factory test (added 11.10.18):
Hold A + B + Select + Start before powering up the console.
Source: tcrf.net

(BUR) Hidden text (added 11.10.18):
There are few unused debut text lines inside the ROM. The First one is an unused copy of the same line for "Factory test" (see above):
RAM banks = ‑
token = controller 2
run_error=‑
Also, the game uses following string for test the CRAM banks of inserted cartridge:
Mushroom/Kingpin

Source: tcrf.net

Megaman IV (USA), Rockman World 4 (Japan)

(BUR) Game genie (added 23.10.18):
1A9‑BAF‑A2A-At the title screen, start a new game to access the debug menu instead. There are a lot of various options to enable all items/weapons, play any stage with either infinite ammo or health.
Source: tcrf.net

Megaman V (USA), Rockman World 5 (Japan)

(BUR) Game genie (added 23.10.18):
C55‑0CF‑2AA+045‑0DF‑E6B-Replaces the Soft-reset code (A + B + Select + Start) with debug menu similar to menu in previsous version (see above). Additionally the message test is available here.
Source: tcrf.net

Megami Tensei Gaiden - Last Bible

(UNI) Secret names (added 24.10.18):
Enter following word as a main character name. Note, that nigori symbols must be input separately.
ポン-Start a new game with strongest combat parameters.

Megami Tensei Gaiden - Last Bible II

(FIX) Secret names (added 24.10.18):
Enter one of the following words as a main character name. Note, that nigori and panigori symbols must be input separately.
ポンです-Start a new game with strongest combat parameters.
Source: urawaza.in
モンスター-Monster viewer will appear when all three character's names are input. All monsters is displayed one by one then return back to the name input screen.

Meitantei Conan - Chika Yuuenchi Satsujin Jiken

(GEN) Secret passwords (added 15.08.16):
MGTEST-Test screen. Allows you to play any mini-games or play the game with all events completed by default.
Source: urawaza.in

Meitantei Conan - Giwaku no Gouka Ressha

(GEN) VIP Room (added 27.10.18):
Start a new game. Solve one of three cases with a best result, get the final password and use it to start another game (if you solve the case wrong or didn't find all the clues you won't get any passwords). Solve the second case also with the password and use it to start a game for the third time. If all three cases are solved right, then the "BETTER ENDING" will be shown following with a Credits. After ending is over, there will be a final message from Conan about Memo found in VIP room safe (VIP passanger suicide case). This is a final riddle of the game, you must solve it to obtain a 6-letter password (in case you can't solve it the password is "3VA DGO"). After the final message, instead of the intro the game starts from the password screen which this time accepts only one correct 6-letter password mentioned before. If all done right, you'll access the secret scenario where you hadn't solve any murder cases but walk around the train and talk to other people.

Meng Huan Zhi Xing (Phantasy Star) (Unlicensed)

(UNI) Stage select (added 28.10.18):
During the intro before the title screen any time, press Up, Up, Down, Up, Left, Right, Left, Right.

(UNI) Instant battle win (added 28.10.18):
During the game at battle press Start, A to instantly set the enemy's HP to 0 thus win the battle immediately.

Mercenary Force (USA, Europe), Tenjin Kaisen (Japan)

(FIX) Title cheats (added 02.11.18):
At the title screen, press one of the following button codes to activate a corresponding effect, then press Start.
A + B + Select + Up-Extra 50000 money in the US version or 1000 money in the Japanese version from the beginning. Also you'll get worst ending when finish the game. Additionally Stage select will be enabled (at the Stage number screen press Right).
Source: gamefaqs.com
A + B + Select + Down-The same as code above but disables the Stage select mode if it is already enabled.
A + B + Left-Hard mode. Enemy bullets are 2 times faster, all the bosses have doubled HP.

Metal Masters

(FIX) Stage skip (added 02.11.18):
During the game, press Start to pause it then enter Up, Right, Up, A, Left, Down. A sound confirms correct code entry. Now, during any fighting stage press Start then A + B to instantly kill the enemy robot and so end the battle. Do the same at the side scroller stages to skip right to the boss.
Source: gamefaqs.com

Metroid II - Return of Samus

(BUR) Game genie (added 08.08.16):
002‑4BB‑5D4-Re-enables the debug mode.
On pause:
Press Left/Right to select item, press A to toggle item.
Press Up/Down to change weapon (valid values are 0,1,2,3,4 and 8).
Hold B, press Left/Right to change max number of energy tanks.
Hold B, press Up/Down to increase max number of missiles by 10 (decreasing only affects current number of missiles), max missiles are 9999, only 999 will be displayed.
Hold A + B, press Left/Right to change the metroids counter.
During the game:
Hold B + Select while transiting between two different locations (i.e. from the starting location to the first cave or back) to jump directly to the Final Boss.
Source: tcrf.net

Mick & Mack as the Global Gladiators (Prototype)

18th January version:

(UNI) Cheat mode (added 30.05.17):
This cheat only exists in the latest known prototype. Pause the game, then press Left, Up, Right, Down, Left, Left, Up, Up, Right, Right, Down, Down, Up, Down. This will toggle the internal cheat flag on or off. If cheat flag is on, the message "ON" will be displayed above the "PAUSE" message. Otherwise you'll see the "OFF" message. When cheat is on you is invulnerable for enemies and its projectiles, but still could die in the water or ground pits and during the last boss battle. Press Select during the game to skip current stage. When you lose the game and return back to the title screen, pressing any button will bring you to the secret developer's message scroller instead of the "OPTIONS" screen. This message is about 1.5Kb in size and cyphered with xor code, so you couldn't see it inside the ROM easily. Also, this cheat replacing the ending screen with the message:
     CHEAT MODE
    WHAT A LOSER


  CODE BY D STONES
 GRAPHICS BY A PANG


Mickey no Tokyo Disneyland - Cinderella-jou Mystery Tour

(UNI) Secret passwords (added 03.11.18):
Note, all these passwords are just some pre-defined states of this game. The same results may be acquired with the valid password generator as well.
TDL
ミシキ
マウス
-"TDL Mickey Mouse". lives 99, balls 999, stage 4-2, ballon lv3, 100% complete, all items.
MMS
PEC
IAL
-"MM Special". lives 55, balls 555. stage 1-1, balloon lv3, 0% complete, no items.

(BUR) Hidden text (added 03.11.18):
There is a Shift-JIS encoded string at 0x251 in the game ROM with a hidden copyright text:
Programed by ATS since 1995


Mickey's Chase

(BUR) Debug leftovers (added 03.11.18):
During the game, write $01 to RAM address $C534. Now press Up/Down to switch between two CHR data banks, press Select to access the Sound test mode. There is no return from here back to the game except reset.

Micro Machines

(UNI) Head to Head mode cheats (added 04.11.18):
Start a new game in "Head to Head" mode either in Tournament or Single Race modes. During the game, press Start to pause it, then enter one of the following codes to get a corresponding effect. If done right, the wave slide down on the screen. Codes may be input multiple times without limits.
Down, Down, Up, Up, Left, Left, Right, Right, Left, Left, Down, Down, Up, Up-Max speed for both players.
Left, Right, Left, Right, Up, Down, Up, Down, Up, Down, Left, Right-Lap 1 for both players.
Up, Down, Left, Right, Up, Down, Left, Right-Lap 9 for both players.

(UNI) Title cheats (added 04.11.18):
At the title screen or either on any demo sequence or demo stage presentation screens (except places where text is typed out), input one of the following button sequences to get a corresponding effect. If done right, the wave slide down on the screen.
Down, Up, Left, Right, Up, Up, Down, Down, Left, Left, Right, Right-Enables the player switch option in any game mode except "Head to Head". During the game press Start then Down to select the player to control.
Also at the title screen or at the demo/presentation sequence press Select to open an Options menu where you can toggle some additional cheat options on and off.
"STATIC" disables CPU AI for all races
"VIDEO" switch off cinematic sequences during the game.
"INFY" sets the infinite lives.
"SKIPPER" allows to select any Challenge mode track instantly instead of playing them one by one sequentially.
Need to investigate what actualy "STD LK" and "HOVER" option are doing.
Left, Left, Right, Right, A + B-"The 15 Puzzle" hidden mini game. The picture here is a Big Red Software logo made by programmer RFredW.
Up, Up, A, B, A, Down, Down-Game credits, same as in the ending.
Right, Right, Left, Left, Up, Up, Down, Down, Right, Left, Up, Down, A + B-Disabled or unfinished cheat, does nothing except accepting the correct code input.

(FIX) Challenge mode secrets (added 04.11.18):
Almost every stage in the Challenge mode (except Tank, Time Bonus, Qualify and Final stages) has a hidden spots on the map where you may get a special prize. What you need is just to press Start at the particular map position. The table below describes complete list of available secret points with its effects as well as explanation how to reach them. The map coordinates are in the basic map chunks area units. For example, a pile of corn flakes on the table within 4 table-cloth squares is exactly one map unit. The top-left corner of the map is a starting point with a coordinates 01,01.
Round|Name|Type|Coords|Effect|Where it is
1|The Breakfast Bends|Four By Four| 9, 5|1st place|There is a napkin in the top-middle side of the track. To bottom-left from it the nearest corn flakes heap.
2|Desktop Dropoff|Sport Cars|11,14|Extra life|In the middle of the gap between two tables when you jump off from the tablet.
Source: gamesradar.com
3|Oilcan Alley|Warriors|23,29|Min friction|At the bottom-right corner of the track, move straigth diagonally down-right until gap filled with nails between two piles of nuts to the right and to the bottom.
4|Sandy Straights|Turbo Wheels| 9,12|Lap 1 |At the last up-right turn after the sand castle before the finishing line. Stand at the river bank corner.
5|Oatmeal in Over-Drive|Four By Four| 1, 1|Min inertia|At top-leftmost position, very close to the table corner.
6|The Cue-Ball Circuit|Formula One|15,23|Extra life|Area around a pale ball above the track at bottom-rightmost hole of the table.
7|Handyman's Curve|Warriors| 5, 4|1st place|At the top-left corner of the track, an area above the Oil tank. Accessible via the gap between nut and the fuze at the bottom-left corner of the oil tank.
9|Sahara Sandpit|Turbo Wheels|16, 8|Min friction|Top-middle part of the track. The lower half of the foot print just below it.
10|The Potted Passage|Choppers| 4,14|Min inertia|From the starting line go straight back. Stand exactly where the tube meets the bushes.
11|Fruit Juce Follies|Four By Four|16,31|1st place|At the middle-bottom part of the track there is a corn flakes box. Stand right below of it exactly under the name and very close to the table bottom side.
12|Foamy Fjords|Powerboats|23,19|Min friction|At the rightmost part of the track, ram into the cap of the Shampoo bottle on the path.
14|Pitfall Pockets|Formula One| 3,26|Min friction|Area around the pale ball near the bottom-left hole of the table.
15|Pencil Plateau|Sport Cars|30,27|Min inertia|Stand at the very bottom-right corner of the small isle where the first jump tablet is located.
16|The Dare-Devil Dunes|Turbo Wheels|25,10|Extra life|At the top-right side of the map, there is a right turn before the road loop with two lakes inside. Instead of getting this turn go straight up and stand very close to the left side of third lake near two lakes in the loop.
17|The Shrubbery Twist|Choppers|17, 9|Min friction|At the right side of the track tere is a fuse box with a switch button at its top-left corner. Try to squeeze inside the bushes right above it.
18|Perilous Pit-Stop|Warriors|12,27|Min inertia|From the starting line go straight up-left to the nearest pencil.
21|Soap-Lake City!|Powerboats| 7,16|Lap 1 |Left-middle side of the track. Stand at upper part of the short tube, just before the bubbles on the route.
23|Chalk-Dust Chicane|Formula One|17,30|Extra life|Stand very close to the bottom right hole of the larger table.

(BUR) Hidden text (added 04.11.18):
There is an unused version string in the last bank in the internal game encoding:
Vsn 3.81 26/8/94


Midori no Makibaou

(BUR) Game genie (added 05.11.18):
000‑80F‑F72-Reset the game to access the debug menu. Here you can listen to the music and sounds, run any game routine including all endings (MAINNO up to 16 are valid values). Select MAINNO==01 to activate simple CHR viewer. Also you can edit horse statistic here.
Source: tcrf.net

Mighty Morphin Power Rangers - The Movie

(GEN) Secret passwords (added 05.11.18):
3844-Ending.
Source: gamefaqs.com

Mikeneko Holmes no Kishidou

(UNI) Password generator (added 08.11.18):
Note, most of flags and values meaning not known currently, need to investigate more. The main value for password is Var 6 which is chapter number from 1 to 5. Other bits are ignored here so they are disabled.
Also here is a secret Flag 23 which allows you to access the Sound test mode. Just generate password with only this one Flag set.
Also note, you may generate the same password as described by urawaza.in if set Flags 1,2,23,24 and also first bits of two vars 1 and 6. This is a default game-generated password but with Sound test Flag set. When this Flag is set, all other Flags and Vars are ignored.
Flags:0102030405060708
0910111213141516
1718192021222324
Vars:1
2
3
4
5
6
password:

Source: urawaza.in

Mini 4 Boy

(GEN) Secret names (added 12.11.18):
Note, there are two names you need to input before the game: a player's name and a car's name. You may input either the secret player's or car's names only, so you'll get just one of the corresponding effects.
しゃちょう-Enter as a Player name. Extra 10000 Money.
パーシいっぱい-Enter as a Car name. Extra parts: s/f/x-chasis, speed/corner aero, n-wheel 2, n-tyre 2/3, n-roller, n-stabilizer, f/s/r-roller set 1, n-plate.
Source: makainyumon.web.fc2.com

Mini 4 Boy II - Final Evolution

(GEN) Extra SGB border (added 12.11.18):
At the "J-Wing" logo screen, press Select 5 times.
Source: tcrf.net

(FIX) Secret names (added 12.11.18):
Input one of following words as a corresponding name.
Word|Name|Effect
ポイント|Player's car name|Extra 800 points at the beginning of the game.
かいはつしゃ|Player's name|Developers names and messages menu.
ゴールド|Player's car name|Extra 8000 money at the beginning of the game.
サウンド|Player's name|Sound test.
Source: tcrf.net

Mini Putt

(BUR) Game genie (added 15.11.18):
233‑14F‑806-Re-enables link mode selection menu before the main game select menu. You can select the regular game on single Game Boy, on two Game Boys linked via cable and the 4-player game with a special adapter. Linked modes are fully functional, so this is unknown why they removed it from the released version.
06C‑2FA‑F7A+03C‑B1A‑E62-Additionally, there is a third game type planned for linked modes: "FIGHT". All coding is still in the ROM, they just removed all additional code to display the selection menu with three game modes in it. Use these two codes in addition to the previous one to re-enable the third mode selection ability. In this mode both players are plays on the field at the same time. Unfirtunately, seems this mode were unfinished or not debugged well. The game hangs after first move.

Mini Yonku GB Let's & Go!!

(BUR) Game genie (added 21.11.18):
07B‑0DB‑F7E-Access the disabled debug menu when hit "START" at the title screen. There are two pages of this menu, at the first one you could enable or disable ingame debug, select one of the system routines for test or watch events. At the second page there are a music and sound tests, parts viewer and some other.

(BUR) Hidden text (added 20.11.18):
There is a hidden copyright text in the Sound engine ROM bank:
DSEQLITE
CRTS(C) mcmxcvi by Toshiyuki Ueno
toshi-u@tau.bekkoame.or.jp

Source: tcrf.net

Mini Yonku GB Let's & Go!! - All-Star Battle Max

(BUR) Hidden text (added 21.11.18):
There is a hidden copyright text in the Sound engine ROM bank:
DSEQLITE
CRTS(C) 1996,1997 by Toshiyuki Ueno
toshi-u@pobox.com

Source: tcrf.net

Miracle Adventure of Esparks - Ushinawareta Seiseki Perivron

(UNI) Power up (added 22.11.18):
During the game, press Start to pause it, then Start + Select + B + Up to unpause and instantly obtain an extra 9 fire-balls and set the scores to xx30xx, so you'll have an instant armor power up. This cheat can be done unlimited amount of times.

Mole Mania (USA), Moguranya (Japan)

(FIX) All items (added 23.11.18):
During the game, press Start to enter the game menu. Hold Select, then press Left, Right, Left, B, B, Right, Left, Right, A, A (for the US version) or Up, Up, Down, Down, Left, Right, Left, Right, B, A (for the Japanese version).
Source: makainyumon.web.fc2.com

(BUR) Hidden text (added 23.11.18):
There is a hidden copyright text near the end of third Sound engine bank:
1996/4/19
PM 5:30
MOGURANYA
SOUND PROGRAM
& MUSIC
& SOUND EFFECTS
ALL DATA WERE
WRITTEN BY
TARO BANDO

Source: tcrf.net

(BUR) Game genie (added 23.11.18):
0F3‑D0B‑E66 (for the US version)
0F3‑DBB‑E66 (for the Japanese version)
-Re-enables the disabled Error message upon starting a game. Original screen written in Japanese, but for all western versions it left untranslated and reads only garbage.
Source: tcrf.net

Momotarou Dengeki

(GEN) Secret passwords (added 24.11.18):
五九六三-Sound test and Object viewer.
Source: urawaza.in

Momotarou Dengeki 2

(UNI) Secret passwords (added 24.11.18):
五九〇一一五 ("590115")-Start a new game on Normal mode with invulnerability.

(BUR) Unused Sound test (added 24.11.18):
During the game in emulator, pause emulation and set RAM address $C0F6 to $01 and $C0F7 to $00. There is no display, only portions of characters will be displayed in place of HUD. You can see something only when start to move cursor and change BGM/SE indexes with D-Pad. Since there is not known how to acces it properly, it will crash after attempting to exit via last menu option.

Momotarou Densetsu Gaiden

(GEN) Soft reset easter (added 27.11.18):
The Soft reset code in this game (hold Start, press Select) not only resets the Game Boy, but also shows the animated "Hudson Soft" logo scrolling down just like the Nintendo logo does at the console boot.
Source: urawaza.in

Monopoly

USA and European versions:

(GEN) License screen skip (added 26.11.18):
To instantly skip the License screen press A + B + Start. The Japanese version allows you to skip it with any button instead.

Monster Maker - Barcode Saga

(UNI) Ending (added 26.11.18):
At the title screen, hold Select, press Up, Right, Down, Left, Up.

Monster Truck

(FIX) Title screen cheats (added 28.11.18):
At the title screen, wait when Truck stops at the center of the screen or press any button to hold it manually. Now you need to press buttons for a corresponding number of times in any order, just make sure you pressed every needed button for a particular number of times. The lists of button and its press counts for every possible cheat combination described in the table below. When done, press Start. All possible combinations and its effects are in table below.
A|B|Select|Right|Left|Up|Down|Effect
1 time|1 time|1 time|1 time|1 time|1 time|1 time|Ending.
Source: urawaza.in
5 times|7 times|-|-|2 times|-|-|Stage select.
1 time|2 times|3 times|5 times|6 times|7 times|8 times|Sound test.

Montezuma's Return!

(GEN) Secret passwords (added 28.11.18):
ELEPHANT-Infinite lives.
SUNSHINE-Unlock all doors.
Source: gamefaqs.com

(BUR) Hidden text (added 28.11.18):
There is a copyright text at the beginning of the ROM:
COPYRIGHT TAKE 2 1998


Mortal Kombat

(UNI) Fixed difficult (added 28.11.18):
Hold A + B then power the console on and wait for the license screen. From now, there will be one fixed difficult level 2 for all battles no matter what current stage is. Difficults are in range from 0 to 9, so this is kinda simplify beating the game.

(FIX) Unlock Goro (added 28.11.18):
Beat the game, wait for the credits are about to over. At the "THE END" message, hold Up + Left + Select + A then wait when this message is disappear. If done right, there will be a Goro picture before the fight (fighter selection menu is skipped, always play as Goro) where in addition to message "GORO LIVES..." an additional line appears at the bottom of the screen "AS YOU...". The difficult for all fights if played with goro is maximum from the beginning (9). Also in this mode, all regular character's names are changed to different names of some devs/designers of Probe Software. Kano turns to Bob, Rayden to Eric, Kang to Carl, Scorpion to Peter, Subzero to Gary, Sonya to Fergus and Tsung turns to Eddy. Also the main title list of battles "BATTLE PLAN" turns to "BRITTLE PLUM". One unused fighter name Cage should turn into Jean but never appears in this game.
Source: gamefaqs.com

Mortal Kombat II

(FIX) Fighter auto select (added 29.11.18):
At the "START GAME" menu option, hold Up, then press and hold Start until Fighter selection menu appears. This will activates random Fighter selection. This works for both players in linked mode game.
Source: gamefaqs.com

(GEN) Hidden text (added 29.11.18):
There is a regular Probe Software copyright string in the Sound engine data bank near the end of the ROM:
(C)Probe.

Source: tcrf.net

Mortal Kombat 3

(GEN) Fighter auto select (added 29.11.18):
At the Fighter selection screen, hold Up and press Start to activate auto Fighter selection.

(GEN) Secret passwords (added 29.11.18):
After the VS screen there is a special screen where you may enter a special codes to enable a corresponding effect to the next fight. Some codes does nothing, just displaying some text. There are also four dummy codes that doesn't even display anything so you just couldn't say they are work. Believe me they does but they are useless.
Idx|Code|Message|Effect
01|100-100|THROWING DISABLED|No throws.
02|020-020|BLOCKING DISABLED|No blocks.
03|033-000|PLAYER 1 HALD POWER|-
04|000-033|PLAYER 2 HALF POWER|-
05|688-422|DARK KOMBAT|Light up only when kick something.
06|460-460|RANDPER KOMBAT|Randomly change both players during the Fight.
07|987-666|HOLD FLIPPERS DURING
CASINO RUN
|Message only.
08|707-000|PLAYER 1 QUARTER POWER|-
09|000-707|PLAYER 2 QUARTER POWER|-
0A|642-468|-|Dummy.
0B|969-141|-|Dummy.
0C|033-564|-|Dummy.
0D|769-342|-|Dummy.
0E|282-282|NO FEAR|Message only.
0F|987-123|NO POWERBALLS|No shooting.
10|466-466|UNLIMITED RUN|No run limit.
11|985-125|PSYCHO KOMBAT|Codes 02, 05, 06, 0F in one at the same time.
12|123-926|THERE IS NO
KNOWLEDGE THAT
IS NO POWER
|Message only.
13|205-205|FIGHT SMOKE|Fight with Smoke.
14|192-234|SMOKE ENABLED|Fight as Smoke.
Source: gamefaqs.com

Mouse Trap Hotel

(FIX) Extra 10 lives (added 30.11.18):
At the title screen, press quickly Up, Down, B, Select, Right then press Start to start a new game.
Source: gamefaqs.com

(UNI) Stage select (added 30.11.18):
Hold Up + Right before power the console on, then wait for the License screen appears. After a license screen you'll see an "ELEVATOR" room instead of the title screen where you can select any starting floor except the last one.

(UNI) Debug menu (added 30.11.18):
During the game, press Select to enter Map mode. Input one of the following button sequences to open a corresponding debug menu.
Up, Down, Right, Up, Down, Left, B, Up, B, Down-Simple debug menu. Select invulnerability, max out lives, Stage select with floor 5 available, start at bonus room.
Up, Down, Right, Start, Up, Down, Left, B, Up, B, Down-Complex debug menu. All options of the simple mode, plus much more debug functionality.

(BUR) Hidden text (added 30.11.18):
There is a hidden copyright string at the beginning of the ROM:
(c) 1990 Milton Bradley by Mark D. Klein 06-11-90

Source: tcrf.net

Mr. Nutz

(GEN) Secret passwords (added 30.11.18):
NESTOR-Stage skip. During the game press Select + Start.
Source: gamefaqs.com

(BUR) Hidden text (added 30.11.18):
There is a build date string near the beginning of the ROM:
MR NUTZ 28 SEPTEMBER 1994


Mysterium

(GEN) Debug cheats (added 01.12.18):
Start a new game, press Select to open "INVENTORY", then select "MAP". Press one of the following button codes to get a corresponding effect.
A + B + Left + Start-Insert a special debug item "PASS KEY" to the inventory. May be used for open any door. Also can be transformed to other debug items when used with any Pool: "DOWNLEVL", "UPLEVEL" and "SUPERPOW" which allows you to go down to the lower/upper floors or grants an invincibility correspondingly.
Select + B + Up-Fills the inventory with a sequential set of items starting from currently posessed item in the first slot. May be used to list all possible items in the game.
Select + B + Down-Doest the same as "DOWNLEVL" item, instantly skips to the lower floor.
Source: gamefaqs.com

Mystical Ninja Starring Goemon (USA), Ganbare Goemon - Kurofunetou no Nazo (Japan)

(BUR) Game genie (added 27.04.17):
011‑F7E‑E6A (for the US version only)-Re-enables some debug features. At the Map screen, press Up/Down to change starting location, press A to continue (delay is disabled). During the game, press A + B + Select to skip the stage instantly. The Japanese version has all the same routines, but there are no variable initialization to hack, but you still can modyfy the RAM address $C067 to any non-zero value to enable them. Also, the stage skip cheat there is different: A + B + Start

Nada Asatarou & Kojima Takeo no Jissen Mahjong Kyoushitsu

(UNI) Cart RAM clear (added 15.09.17):
In addition to the generic soft-reset button code (A + B + Select + Start), hold Up to not only to reset the console but to clear the saved game data as well.

(UNI) Forbidden names (added 15.09.17):
This game has a hidden check for the name you enter in the Tournament mode. If it match with one of the words, then it will be replaced to another one rather less obscure i think. The full list of replacements in the table below.
Forbidden name-Replacement
"ああああ" (generic "lazy" name)-"あなた" (literally "you")
"    " (all spaces)-"ひろきゅ" (-)
"おまんこ" ("pussy")-"すけべ" ("lecher")
"せっくす" ("sex")-"えっち‥" ("pervert")

Nakajima Satoru - F-1 Hero GB - World Championship '91

(UNI) Password generator (added 29.03.17):
Note, that there are no passwords given to you by the game after completing Level 8, but the password generation system supports level numbers up to 9, which renders as a special secret case to see an instant ending.
Team:
Level:
Random:
password:


Namco Gallery Vol.1 - Battle City

(BUR) Game genie (added 09.12.18):
There are a couple of debug leftovers disabled in the release version. Both working in "FIX MODE" only, "NORMAL MODE" does not have any debug leftovers.
CA2‑B0B‑E65-Press B to instantly exit current stage and return to the stage select screen.
CA2‑D3B‑E65-Press Select to force the random item to appear on the field.

Namco Gallery Vol.1 - Mappy

(BUR) Game genie (added 09.12.18):
000‑0BB‑80A+000‑0CB‑B3E-Re-enables "DEBUG" mode. During the game, press Select to enter the Debug mode menu, select stage and press Select again to play it, select music and press A to listen to it.

Nectaris GB

(GEN) Quick start mode (added 14.05.17):
This mode is unlockable. When you complete all Story and all Legend modes, the "QUICK START" option will appear in the game's "MAIN MENU". This option allows you to play any both Story and Legend maps either in 1PLAYER or 2PLAYER (on the same GB console in turns) modes. Also, you can choose here to play as "GUICY" instead of "UNION" on the same regular maps, just like in the PCE version.

(GEN) Secret passwords (added 14.05.17):
Note, two secret sets of passwords enables the Advanced maps for both regular game modes. All passwords here are just regular passwords for the corresponding maps written backwards. Also, there is a set of 44 secret passwords for every Campaign Mode maps available in GB version: "EMAPxx", where "xx" is a map number from 01 to 44 (last four corresponds to the "SPWinners" maps), but since they can be accessed at any time from the "Campaign maps" menu, they are actually don't needed.
-Story Maps Advanced (GB Exclusive)
NEVETS-Map 01
LARTSA-Map 02
ELKCEH-Map 03
GNIMER-Map 04
REYETS-Map 05
EHTLAW-Map 06
TUBMUN-Map 07
FATSUG-Map 08
CIDRAD-Map 09
ELLSEK-Map 10
YNWORB-Map 11
OTEREB-Map 12
RENERG-Map 13
TREGER-Map 14
AMALAS-Map 15
TCENOZ-Map 16
-Legend Maps Advanced (PCE Campaign)
TLOVER-Map 01
SURACI-Map 02
ONARYC-Map 03
YESMAR-Map 04
NOTWEN-Map 05
ACENES-Map 06
ENIBAS-Map 07
SUTARA-Map 08
SIOLAG-Map 09
NIWRAD-Map 10
LACSAP-Map 11
YELLAH-Map 12
NAMROB-Map 13
OLOPPA-Map 14
RESIAK-Map 15
ROTCEN-Map 16
Source: nectaris.tg-16.com

Nikkan Berutomo Club

(UNI) Cheat sequences (added 08.07.16):
All cheats entered at the title screen and has effect during the gameplay. Enter one of the following sequences and either start a new game or continue previously saved one. You may notice if cheat is working (except fot the first one, see below), in the main display header, day of the week will be separated with line from the time, otherwise there are no characters between them.
Start, B, Start, Select, B, B, Select, Start-Add all friends to list instantly at the game start. After all friends are added, the cheat flag is set to zero and does no extra functions or indications.
Select, Select, B, Start, Start, B, Select, Start-At the main game menu, hold Down, then press Select to enter the Sound test.
B, Start, B, Start, Select, B, B, Start-This is most powerful debug cheat here. First, any time during the game, hold Select + Start to skip 2 minutes of time every second.
At the Main game menu, hold Down, then press Select to enter the debug menu. Here you can select some of game events, including ending and staff displays, sound test and debug memory viewer.
At the Friends list, hold Select or Start, then press Up/Down to increase/decrease the friendship level correspondingly. A number under the friend's face will indicate the friendship level. If there is no friend at the selected position, it will be added.

NIV Holy Bible, The (Wisdon Tree, Unlicensed)

(GEN) Word Match Game Level select (added 18.11.18):
At the Word Match Game Title screen, hold Up, then press Select to increase starting game level.

(UNI) Checksum test (added 18.11.18):
At the main menu, press Left 8 times. A sound informs you when checksumming started and finished. Since this is a leftover from the original version of this cartridge "King James Bible", the checksum is displayed at the same place but there are no ROM version anymore, so it overwrites some random text.

Otto's Ottifanten - Baby Bruno's Nightmare (Europe), Adventures of Pinocchio, The (Prototype)

All versions:

(UNI) Secret passwords:
PQLLQ-Stage select. Dugint the game, on pause, press Up or Down to change current room number, room 101 is an ending. Unpause to jump to it. In the prototype version this cheat is enabled by default.
ZYDRQ-Secret message 1.
RQB1N-Secret message 2. This screen is different in prototype. The version of this screen from release used in many other games by the same developers Bit Managers.

Prototype version:

(BUR) Game genie:
201‑F2F‑19F+003‑7CF‑C4D-Re-enables an unused "Electro Brain" logo at start.

Oyatsu Quiz Mogu Mogu Q

(UNI) Sound test (added 23.02.18):
At the Star-Fish logo, hold Select + A + Left and wait for the Sound test screen appears.

(UNI) Debug mode (added 23.02.18):
At the Star-Fish logo, quickly press Select, Up, Down, A, Left, Start. When the screen fades out, a message "DEBUG MODE / DEVELOPMENT STUFF ONLY" will be displayed. Now you can access the debug menu during the game by holding Select at the beginning of some events or while in transition between game screens.
In "DEBUG MENU" you may access a the same Sound test as in cheat above, also all quiz tests, setup items, generate a password, watch an ending or toggle on or off the "MUTEKI" mode where you can't loose on any quiz sequence.
There are other debug features:Press Start any time to pause the game instantly.
At the passwords input screen, enter password of all "あ" to instantly return back to the title screen.

Pagemaster, The

(UNI) Cheat flags (added 29.09.18):
At the main game menu, enter Up, Down, Right, Left, Down, Up, Left, Right. A new menu option "CHEAT FLAGS" will appear. You can toggle on the infinite lives, stage skip and items select.
Source: nensondubois, tcrf.net

(UNI) Easter egg (added 29.09.18):
Enter the "Cheat flags" code sequence. Do not enter the cheat flags menu, still being at the main menu enter two more sequences: Down, Down, Right, Up, Left, Left, Down, Right then Up, Up, Left, Down, Right, Right, Up, Left. After every code the sound will confirm correct input. The first code changes the deadly objects in the Bonus stage to faces which appears to be a Fergus heads from the Mortal Kombat series. The second one also changes the main character when in the Bonus stage into something like penis. The second code may be entered only after the first one, you can't just change main character into penis only.
Source: nensondubois, tcrf.net

(UNI) Credits (added 29.09.18):
At the main game menu, enter Up, Right, Down, Left, Up, Left, Down, Right.

Panel no Ninja Kesamaru

(UNI) Secret passwords (added 17.10.17):
Two of three working secret cheats skips to the main menu upon succesfull entering without indication. You can either start a new game or enter any other passwords including the secret one. All effects are combined.
5-9-6-3-Ending.
1-1-2-0-Invulnerability to all enemies and its projectiles.
8-8-1-6-Trainig mode. At the Stage select screen, press Select to switch castles, press B to skip to the second part of levels for current castle. Beating the stage in this mode does not removes it from selection. So you can play any stage, but can't save any results.

Peke to Poko no Daruman Busters

(UNI) End level (added 20.01.17):
At the game setup screen in 1P mode, press B at least 150 times (but not much than 255). Now press Select to change the starting level up to END, the final level, which is normally can't be selected.

(BUR) Game genie (added 20.01.17):
80F‑FFC‑E6A-Re-enables a debug leftovers. Now, any time during the game press Left + Select to hold the game on pause without cleaning the screen, press any button to return to normal state. Additionally, you can select the END level at the game setup screen without cheat.

Penguin Wars (USA), King of the Zoo (Europe), Penguin-kun Wars VS (Japan)

(FIX) Level select (added 12.08.18):
At the player select menu, hold Left + B and press A. A number will appear at the bottom-right corner of the screen. Press Up/Down to change it. The resulting Game number equals to (selected number - 1) times 4 plus 1 (for exmple selection 02 means (02-1)*4+1=5th game, or 10 means (10-1)*4+1=37th game - which is max game number here). Press A to begin the game.
Source: gamefaqs.com

(UNI) Sound test (added 12.08.18):
At the player select menu, press Select + B at the same time to change currently playing background music. There are total 12 tracks. After track 12th music will warp back to the first track.

(UNI) Play with the same character (added 12.08.18):
There is an option to play against the same character as yours but for some reason it is possble only on Level 22. After beating level 21, hold B and wait for the "YOU WON THE SET!" message appear.

Picross 2

(GEN) Instant demo sequence (added 15.09.18):
At the title screen, press A + B to instantly switch to one of two demo sequences without waiting for them.
Source: urawaza.in

(UNI) Simple rulers (added 14.09.18):
During the game, hold B, press Select to toggle between simple kind of rulers and the regular ones. The simple kind does not magnify the numbers in highlighted rows/colums and also blinking. The similar type of rulers were used in the first part of this game.

(FIX) CRAM clear (added 14.09.18):
To erase an individual save slot, at the "DATA SELECT" screen, put cursor to slot to be erased and hold A + B + Select for a while, then press A when game asks. To erase all saved data at once, before powering the console, hold Up + Left + Select then power it up. Game will ask "ERASE?". Press corresponding button to agree or decline.
Source: gamefaqs.com

(GEN) SGB extra border palettes (added 14.09.18):
In SGB mode, at the title screen, hold one of following buttons and press Start to change default border to "GAMEBOY POCKET" border with a corresponding color:
Up-Black
Down-Yellow
Left-Green
Right-Red
B-Gray
Select-White
Source: gamefaqs.com

(BUR) Hidden text (added 14.09.18):
The game uses following name as part of the internal RAM signature:
Ogata Kitawaki
Also the sound engine bank contains copyrights of the composer:
DSEQLITE
CRTS(C) mcmxcvi by Toshiyuki Ueno
toshi-u@tau.bekkoame.or.jp

Source: tcrf.net

(BUR) Game genie (added 14.09.18):
010‑2D8‑F72-Re-enables rather unfinished debug menu. At the title screen, press A + B, the Debug menu appears instead of the demo sequence. The graphics is broken somehow. Most options except "BGM"/"SE" does not work properly. The "TIME" options does absolutely nothing, it's dummied. The "KEY" option displays sprites one by one, but since there is no CHR data set for any of them you'll see mostly text among the garbage. It seems this code were intended to be accessible via title screen codes like "Instant demo sequence" code. When you press A + B at the title, the internal variable gets one of two non-zero values: 5 and 6 for demo and instructions screens correspondingly. There are more values that game checks: 1 for debug menu (used in code above), 4 for ending, 7 for stage clear screen and any other non-zero value to play final puzzle. You may test them if replace first "01" in aforementioned Game genie code with a corresponding number.
Source: tcrf.net

Pocket Bomberman

(UNI) Secret power-up (added 12.05.17):
At the Stage name and number screen in normal game mode, press Left, Right, Left, Right, Up, Down, Up, Down, B, Left, B, Right, B, Up, B, Down, then press Start or A to begin to play. This will enable the special in-game counter which counts the bombs you placed on the stage. When counter reaches the predefined value (different for every area), the sound will be heard and a small flower-like prize will appear near the exit door. Get it to power-up to MAX bomb count, MAX explosion range and get the manual controlled primer. Note, this cheat works only for areas 1 to 4, and if bombs count and explosion range both less than 3. Also note, when you dies or moves to the next stage, the secret is resetting, so you must input the cheat again. The following table contains a numbers of the bombs needed to be placed on every area in order to obtain the Secret power-up.
|Area 1|Area 2|Area 3|Area 4
World 1|10|20|30|15
World 2|20|30|40|15
World 3|20|30|30|15
World 4|15|20|30|20
World 5|20|30|10|20

(BUR) Game genie (added 12.05.17):
0F2‑BDC‑E6E-Restores the disabled Debug menu at the game's boot-up. Note, you just couldn't see any readable text due to lack of proper font, to fix you need to hack it in manually.
Source: tcrf.net

Pop Up (USA), Cool Ball (Europe)

(UNI) Secret passwords (added 25.11.16):
1NDRQLLQ-Extra 99 Water, 99 Hammers and 99 Keys, Infinite lives and Stage select (in the pause mode press Up/Down).

Prehistorik Man (USA), P-Man (Japan)

(UNI) Intro screen cheats (added 09.01.18):
At the "PROUDLY PRESENTS" screen, enter one of the following cheat sequences to get the corresponding effect.
Down, A, Up, B, Left, Right, B, A, B, A, B, A, Up, Down-The 3D scroller with text "CHEATED - YOU HAVE ACTIVATED THE CHEAT MODE MAY ETERNAL LIFE BE YOUR'S" will be displayed. From now you is fully invulnerable. Also Select during the game to skips the current level (working on the boss stages as well).
Source: gamefaqs.com
Left, Right, B, A, Up, Down, A, B, Right, Left-The 3D scroller with the secret developer message will be displayed. You can't skip this scroller unless you reset the GameBoy. The full text of this message you can see below. For convinience all 5-character spaces are converted to line breaks. The actual text have no lines at all.
PICT OF LOGON PRESENTS YOU THIS OTHER PART OF THE DEMO. THE 3D SCROLL DEMO.
WELCOME TO THE AMSTRAD CHEAT! EVERYBODY WANTS TO BE GREETED IN A GAMEBOY GAME,I KNOW..
GREETINX TO..
ALL CPC FREAX!   VERY SPECIAL THANX TO..
BSC
AND
KANGAROO MUSIQUE OF HJT. WITHOUT BSC'S SOUNDTRAKKER AND KANGAROO'S COMPOSING ABILITIES THERE WOULD NOT BE ANY COOL MUSIC IN THIS GAME. DANKE THORSTI UND OLLI!
IF YOU DO NOT KNOW WHAT I AM TALKING ABOUT..
THE AMSTRAD CPC IS AN 8 BIT HOME COMPUTER AND WAS PUBLISHED IN EUROPE BACK IN 1984. IT IS LIKE A GAMEBOY WITH COLOUR SCREEN AND KEYBOARD.
MEMORY FULL,BYE...

(BUR) Game Genie (added 09.01.18):
00D‑658‑6EA+00D‑668‑D5A-There is a working crash handler inside both regional versions of this game. Two working asserts are exists on the Boss stage, checking some parameters to be valid. If not, the crash handler will be displayed. With these codes you can trigger one of the checks and see this crash handler as soon as reaches the Boss stage.
Source: tcrf.net

(BUR) Cheat protection (added 09.01.18):
There is a hidden simple cheat device detection in this game. When you losing a life or HP, code will compare both parameters against its previous values after decrementing them. If values are still the same (so you must be using some device to freeze memory values like Game Genie or Game Shark), the message "YOUR GAMEBOY IS FITTED WITH EQUIPMENT THAT IS INCOMPATIBLE WITH THIS GAME" will be displayed as the same 3D scroller as in cheats above. The scroller is can't be skipped as well as the secret message unless you reset the GameBoy.

Quiz Nihon Mukashibanashi - Athena no Hatena

(GEN) Secret passwords (added 04.06.16):
ZXTB or GSXR-Sound test.
Source: urawaza.in, tcrf.net

(BUR) Game genie (added 04.06.16):
011‑95F‑E6A-Re-enables the quiz questions test mode.

Rampart

(BUR) Game genie:
5F3‑CEB‑7FC-Select 1 PLAYER game, then enter options. The Sound test will appear instead.
Source: tcrf.net

Sachen 4-in-1 Vol. 1 - Street Rider (Unlicensed)

(BUR) Game genie (added 13.05.16):
5C2‑28F‑7F6+F72‑27F‑F7B-Unless many other games by Commin, this one has a fully functional "Creatronic" logo, which may be easily re-enabled by these codes.

Sachen 4-in-1 Vol. 5 - Magical Tower (Unlicensed)

(BUR) Game genie (added 12.05.16):
112‑6AF‑B32+252‑69F‑E64-Re-enables the unused "Mega Duck" logo at the game boot.

Sachen 4-in-1 Vol. 5 - Worm Visitor (Unlicensed)

(UNI) Ending and credits (added 12.05.16):
At the title screen, hold A, press and release B twice, release A, hold B, press and release A twice, release B, finally press Start.

(UNI) Secret credits (added 12.05.16):
Complete the game, or just enter the "Ending and credits" cheat as described above. At the credits roll, enter the same cheat again to acces the secret ending with more deveoloper names in Chinese.

Sachen 4-in-1 Vol. 6 - 2nd Space (Unlicensed)

(UNI) Stage select (added 10.05.16):
At the title screen, when message "PUSH START" appears, press Down + A + B + Select. Now, and the Stage number screen press Left or Down to select any level.

(BUR) Game genie (added 10.05.16):
052‑A5F‑E66+B92‑A4F‑4CE-Re-enables the unused "Mega Duck" logo at the game boot.

Sachen 4-in-1 Vol. 6 - A-Force (Unlicensed)

(BUR) Unused cheat:
At the title screen, press Select, A, A, B, B, Down, Up, Left, Right, Select. The new game is starting immediately. There are no other effects except a sound effect, which seems immediately overwries with the new game start sound.

(BUR) Game genie (added 11.05.16):
6E7‑608‑E6A+637‑5F8‑B34-Re-enables somehow the unused "Creatronic" logo instead of the stage screen. Due to lack of proper initialization code, it need more hacking to properly display without glitches during the game.

Sachen 4-in-1 Vol. 6 - Black Forest Tale (Unlicensed)

(UNI) Credits (added 11.05.16):
At the title screen, Hold A, press and release B twice, release A, hold B, press and release A twice, release B.

(UNI) Restore lives, money and items (added 11.05.16):
During the game, face the character in northern direction, press Start, then press Up + A + B + Select. An extra 9 lives, 111 coins and all powerups will be refilled.

(BUR) Game genie (added 11.05.16):
420‑1AB‑E66+050‑19B‑6EB-Re-enables the unused "Mega Duck" logo at the game boot.

Sachen 4-in-1 Vol. 7 - Ant Soldiers (Unlicensed)

(UNI) Ending (added 13.05.16):
At the title screen, hold A, press and release B twice, release A, hold B, press and release A twice, release B, finally press Start.

(UNI) Level skip (added 14.05.16):
During the game, press Start to pause then hold A, press and release B twice, release A, hold B, press and release A twice, release B.

(BUR) Hidden text (added 13.05.16):
There is a hidden version number string at the beginning of the ROM:
93/06/03VER:002

Source: tcrf.net

Sachen 4-in-1 Vol. 7 - Dan Laser (Unlicensed)

(GEN) Stage select (added 16.05.16):
At the title screen, press A + B + Select + Start. Numbers from 1 to 7 is a regular levels, number 8 is an ending, number 9 is a special credits screen, never seen an any other way in this game. Cheat itself is unlockable and is given to you by the game if you finish it once.

(UNI) Maximum powerups and restore lives (added 16.05.16):
During the game, press Start to pause it then hold A, press and release B twice, release A, hold B, press and release A twice, release B. Press Start to unpause the game, and you'll obtain full weapons, powerups and restore lives to 9.

(BUR) Hidden text (added 16.05.16):
There is a hidden build date string at the beginning of the ROM:
SHOOT ! 93/07/19

Source: tcrf.net

Sachen 4-in-1 Vol. 7 - Zoo Block (Unlicensed)

(GEN) Ending (added 17.05.16):
At the title screen, press Left, Right, A, Right, Left, B.
Source: gamefaqs.com

Sachen 4-in-1 Vol. 8 - Explosive Brick (Unlicensed)

(GEN) Extra stage 33 (added 17.05.16):
At the title screen, press Left, Left, A, Right, Right, B.
Source: gamefaqs.com

(GEN) Extra stage 34 (added 17.05.16):
At the title screen, press Right, Right, A, Left, Left, B.
Source: gamefaqs.com

(GEN) Credits (added 17.05.16):
At the title screen, press Left, Right, A, Right, Left, B.
Source: gamefaqs.com

Sachen 4-in-1 Vol. 8 - Magic Maze (Unlicensed)

(BUR) Game genie (added 17.05.16):
402‑3AF‑5DD+4F2‑3BF‑B3A-Unless many other games by Commin, this one has a fully functional "Creatronic" logo, which may be re-enabled somehow by these codes. Unfortunately, this code does not allow you play the game.

Sachen 4-in-1 Vol. 9 - Crazy Burger (Unlicensed)

(GEN) Ending (added 17.05.16):
At the title screen, press B, A, B, B, A, A, B, B, Select, then start a new game.
Source: gamefaqs.com

Sachen 4-in-1 Vol. 9 - Deep: Final Mission (Unlicensed)

(BUR) Game genie (added 17.05.16):
4B2‑13F‑A2B+052‑14F‑C4E-Re-enable an unused Mega Duck logo at game boot. Unfortunately, this code does not allow you play the game.

Sea Battle (Europe), Schiffe Versenken (Germany), Bataille Navale (France)

(UNI) Secret message:
Wait for the demonstration starts after the title screen. On the developers credits screen, hold Up + Right + Start. While screen is white, release Right only. You'll see a dedication screen the same as in many other Bit Manager's games.

Shippuu! Iron League

(UNI) Password generator (added 29.06.17):
Note, the Time Attack passwords are only for displaying results of your run, the "Stage" field ignored. On the other hand, the "Time" field ignored in Story Mode. However, both fields can be set to any valid value in both password types.
Game Type:
Level:
Time:
Random:
Password:


Spanky's Quest (USA, Europe), Lucky Monkey (Japan)

All versions:

(GEN) Secret passwords (added 29.08.18):
0117-Sound test.
0119-Stage select.
Source: gamefaqs.com

Japanese version:

(GEN) Invulnerability (added 29.08.18):
During the game, pause it with Start then press A, A, A, A, B, B, B, B, A, B, A, B, A, B, A, B.
Source: makainyumon.web.fc2.com

Splitz (USA, Europe, Japan), Uchiiwai - Kyoudaijingi no Puzzle Game (Japan Rerelease)

(UNI) Infinite lives (added 20.08.18):
At the license screen, press Up, Right, Down, Left, A, Start. If done right, the screen will flash for a half of a second. Note, when you commit Suicide manually (Select on pause) you'll get an instant game over even if cheat is active.

Sports Illustrated - Golf Classic (USA), Golf Classic (Europe)

(UNI) Soft-reset enable (added 04.06.17):
At the "ADDITIONAL TESTING" screen, press Select + Left. This will enables the Soft-reset feature. To use it during the game, press A + B + Select + Start. Weird enough this feature need to be hidden under the button code, since most of the GB games has this functionality enabled always by default with just little variations.

(UNI) Cheat mode (added 04.06.17):
At the License screen, quickly (in less than 8 seconds) hold A, press Right, release all, hold A + B, press Up, release all, hold B, press Left, release all and hold A + B, press Down. A sound will confirm correct code entry. Cheat mode enables a lot of new features:
During the game hold Select, press B to skip to the next hole instantly.
When ball is falls into the water, there is a different icon is displayed ("H2O").
When "FAIRWAY" menu is displayed, there is an additional animated character pointing to the menu options from the right side of the screen.
Also, var $D174 set to 2 instead of 1 by default. Used at the game start and before any "FAIRWAY" menu. Investigate.
At the Game select menu hold Right before selecting any option, var $D174 will be set to $F0. Investigate more.


(UNI) Secret courses (added 04.06.17):
First, enable the Cheat mode as described above. Then you need to press a particular buttons to skip next four screens after the License screen. At the title screen, when the scroll is stopped, press Select. At the "DEVELOPED BY" screen, press Start. At the "MUSIC AND SOUNDS BY" screen, press B. And finally, at "EXECUTIVE PRODUCER" screen press A. From now there are two extra Secret courses will be available. Note, two first courses now has a different names at the Course select screen. For two Secret courses the Hole select and Hole skip functions are disabled by default. To enable the Hole select mode, hold Left before selecting the player mode. To enable the Hole skip mode, hold Right before selecting the player name.

Spot - The Cool Adventure (USA, Japan), McDonaldland (Europe)

(UNI) Cheat mode (added 17.09.18):
At the players/difficulty selection stage, hold B, jump 10 times (press A). There is no indication of enabing this cheat. Available now options are described in table below during the game.
Button code|Effect|Notes
Hold B, press Select.|Skip to the next stage.|When used at difficulty selection stage jumps to very end of the game, since the stage index of this screen is previous to final stages and ending.
Press Start.|Instant unlimited high jump|Pause mode not available anymore. The one single default bonus jump with Select still available in this case.
Hold Select, press Up|Toggles infinite health.|-
Hold Select, press Left|Display easter developer picture.|Only accessible at difficulty selection stage.
Hold Select + A, press D-Pad buttons|Free walk mode.|Works weirdly sometimes may stuck in the wall. Also works on the owerworld mode but may glitch even worse.
Hold B, press Start|Complete current stage.|-
Hold A, press Select|Fast forward.|Throws character about 100 pixels forward on the stage without collision tests. So you may just fly the whole level up to the end very quickly or avoid specific obstacles.

Super B-Daman - Fighting Phoenix

(BUR) Game genie (added 14.05.17):
013‑09F‑E6A-Enables a couple of debug features:
Any time during the game, hold Select, then press B to stop the game. Press B to unhold it back.
Hold A + B + Select, then press Start to soft-reset the game.
During the game in "BiDa" mode, press Select to enter the "TEST MODE SET" where you can change the parameters of the current stage.
At the Mode select menu, select the "Caravan mode", hold Select and press A or Start to see the ending.
During the game in the "Caravan mode", hold Select and press Start to instantly return back to the Mode selection menu.
In "JBA" mode, enter the "BINGO" screen, press Start to instantly see the item at the corresponding bingo position.
At the "JBA" mode select screen, put cursor to "Data Save" option, hold Select and press A or Start to enter the Bingo field edit mode.

Super Chase H.Q.

(BUR) Game genie (added 25.08.16):
088‑F2F‑082-Re-enables the Stage select mode at the title screen upon starting a new 1p game.
0D8‑F2F‑082-Re-enables the Sound test mdoe at the title screen upon starting a new 1p game.
469‑06F‑D51+679‑07F‑C47-Show an unused "SIO ERROR" screen instead of Options menu.
Source: tcrf.net

Super Hunchback

(UNI) Test mode (added 10.06.16):
At the title screen, hold Select, then press Right, Right, Left, Left, A, B, Up, Down. You'll be able to select any stage, see the ending and obtain an infinite lives.
Source: tcrf.net

TaleSpin

(GEN) Stage select (added 28.02.17):
At the title screen, hold Down + Left + A, then press Start.
Source: gamefaqs.com

(UNI) Invulnerability (added 28.02.17):
Enter the Stage select mode as described above. Choose any stage, then hold A + B and press Start. You'll be fully invulnerable to enemies and its projectiles, but still can stuck in the obstacles. Additionally, if choose a Bonus stage you'll see the secret message "THANKS YOU FOR PLAYING" after this stage is over. Note, this is not an actual Bonus stage, there is no scroll and you couldn't collect any items, you just can wait for the timer is over or skip it with Left + Right + Down buttons at the same time.

Tamagotchi (USA, France), Game de Hakken!! Tamagotchi (Japan)

(GEN) Cart RAM clear (added 08.05.18):
At the title screen, enter "OPTION", then "Memory". Hold Up + Select and press A. Release all buttons, game will reset with all data clear.

(GEN) Sound test (added 10.05.18):
Win any tournament, then go to the "OPTION" menu and choose new option "Music" to access Sound test.
Source: gamefaqs.com

(GEN) Extra status indicators (added 08.05.18):
During the game, enter "STATUS" screen, hold Down + Select, then press A to toggle on and off the additional status indicators at the bottom-left corner of the screen. This will display "Fear" and "Mine" parameters.
Source: urawaza.in

Teenage Mutant Ninja Turtles - Fall of the Foot Clan (USA), Teenage Mutant Hero Turtles - Fall of the Foot Clan (Europe), Teenage Mutant Ninja Turtles (Japan)

(GEN) Refill energy (added 19.06.16):
During the game, press Start to pause it, then enter Up, Up, Down, Down, Left, Right, Left, Right, B, A. This can be done only once per game, however.
Source: gamefaqs.com

(GEN) Hidden minigames (added 19.06.16):
At the Configuration screen, press A + B + Select. A question mark will appear next to the 5th stage option. Select it to be able to play one of the three hidden minigames.
Source: gamefaqs.com

Teenage Mutant Ninja Turtles III - Radical Rescue (USA), Teenage Mutant Hero Turtles III - Radical Rescue (Europe), Teenage Mutant Ninja Turtles 3 - Turtles Kikiippatsu (Japan)

(BUR) Game genie (added 21.06.16):
E8B‑40F‑809+37B‑41F‑E6A+357‑E9C‑2A6 (for the US version)
7BB‑43F‑809+37B‑44F‑E6A+357‑7CC‑2A6 (for the Japanese version)
-Re-enables a simple Debug mode. To activate it, press Down + Select any time. Additional Game genie code needed to fix somehow the auto-lock of this handler to itself.
However, the code still may be locked up if you press the same combination being in the Debug mode. To exit it use only the Select button!
While in the Debug mode, during the game:
Right - toggles the Invulnerability on/off.
Down - gives an extra Pizza.
A - sets some vars, need to investigate.
Start - toggles the Free mvement mode on/off
...or at the Password screen:
Up - starts some kind of a counter on the password string, presumably used at the developement stage.

Track Meet (USA, Japan), Litti's Summer Sports (Germany)

(FIX) Secret names (added 24.08.18):
Input one of following words as a player name to get a corresponding effect.
"APPLEII"-Activates "APPLE II" banner on the background border. Note, there are no banners at all in the German version so this name does nothing there.
Source: gamefaqs.com
"HEINEMAN"-This is a name of developer. Working exactly the same as previous.
"SNAKE"-Start to play with "IRWIN.B CHEETIN", a 4th opponent. Also activates "SNAKE WUZ HERE" banner in place of previously mentioned "APPLE II" banner. Note, the same as with previous names in the German version, there are no banners at all.
Source: gamefaqs.com
"WORMY"-Start to play with "SWAMMI PASTRAMI", a 2nd opponent. The only actually cheating secret name here. It adds an extra instant 150 points to the player at any result screen.
"REGRUB"-"BURGER" backwards. Start to play with "JACK STROB", a 5th opponent.
Source: gamefaqs.com

(BUR) Hidden text (added 23.08.18):
There is a hidden developer's message near the beginning of the ROM which explains the "ALLPE II" banner:
Created on an Apple IIgs personal Computer.
Apple II Infinitum!


Turok - Battle of the Bionosaurs

(UNI) Sound test:
At the title screen, put cursor to "PASSWORD", then hold Up and press Start.

(FIX) Secret passwords:
ZYDRTRKWPS-Infinite ammo.
ZYDRTRKLVS-Infinite lives.
ZYDRTRKNRG-Infinite energy.
ZYDRTRKBRD-Bird mode. During the game hold Select, then press A. Move your character to any position. Hold Select and press A again to put it back.
ZYDRTRKLVL-Stage select. On pause, press A + B.
CGRZYDLYNY-Secret message. Although it says "BAD PASSWORD", hold Up + Right + B before exit back to the title screen and press Start so see a dedications screen, same as in other Bit Manager's games.
Source: gamefaqs.com

(BUR) Game genie:
009‑1CA‑80A+009‑1DA‑D55 (for the US version)-Replaces the pause during the game with Frame advance mode. Press Start, then Select to advance to the next frame.
489‑16A‑D5F-Re-enables the debug memory view. With this code and the Stage select password, press A + B on pause to enter it.

Wario Blast Featuring Bomberman! (USA), Bomberman GB (Japan)

(FIX) Secret passwords (added 25.07.16):
4622 (for all versions)-Start game powered up with Bomberman
5656 (for all versions)-The Battle mode with Bomberman
2264 (for the US version only)-Start game powered up with Wario
6565 (for the US version only)-The Battle mode with Wario
Source: gamefaqs.com

We're Back! - A Dinosaur's Story (USA), Baby T-Rex (Europe), Agro Soar (Australia), Bamse (Sweden)

(FIX) Cheat sequences:
All cheats should be entered at the title screen. You can enter any number of cheats, all effects will be combined.
Select, A, Down, B, Up, Down-Infinite lives.
Up, Down, Up, B, Left, B-Infinite time.
Select, Up, Up, Select, Left, Left-Stage select.
Right, A, Down, Right, A, Down-Invulnerability.
B, A, Right, B, A, Right, A-Infinite projectiles.
Up, B, A, Down, B, A-All cutscenes and Credits. This cheat is actually working only in the Australian and the European versions. Other versions has it, but entering this cheat will hang the game. However, for the Sweden version the Game genie code 002‑7EF‑C4D may be used to re-enable it, but unfortunately you can see only the last cutscene screen which is replaces the Credits in this version.
Left, A, Left, B, Left-Credits. This cheat actually working only in European version. There is no such cheat in Australian version at all, for the rest of regional versions this cheat should show the credits, but does the same as a previous one: nothing (unless you are using the Game genie code for the Sweden version).
Source: gamefaqs.com

Yoshi's Cookie (USA, Europe), Yoshi no Cookie (Japan)

(BUR) Game genie (added 13.09.18):
001‑DFF$dA2A (for the US version)
001‑CCF‑A2A (for the Japanese version)
-Re-enables the debug menu where you can select any starting level, watch all cutscenes and endings and listen to all music and sounds.
Source: tcrf.net

 

Designed with LAYOUT TECHNIQUES by www.glish.com/css