Yu-Gi-Oh! Duel Monsters 4: Battle of Great Duelist

Yu-Gi-Oh! Duel Monsters 4: Battle of Great Duelist Jonouchi, Kaiba, and Yuugi Decks
Developer: Konami Computer Entertainment Japan Publisher: Konami Platform: Game Boy Color Released in JP: December 7, 2000 This game has debugging material. This game has a hidden sound test. This game has a Data Crystal page

This came out only five months after the previous game and has not one, but three different versions.

Debug Menus

The two debugging menus function similarly to the previous entries. To access these in any of the three versions, use the Game Genie codes 064-16B-F7A and 074-00B-F7E, or modify offset 0x10400 to 07 and offset 0x10416 to 06 in the ROM.

Sound Test

Choose to listen to either the songs (きょく) or sound effects (おと). Music goes up to 34, while sound goes up to 25. The only controls are A to play a song, and B to exit back to the menu.

Character Animation Viewer

View all of the opponents' cutscene animations, which can be viewed by pressing A. The index only goes up to 23. Anything higher and the game sends the player back to the menu. However, no matter who is selected, some random digits are printed onto the screen as placeholder dialogue.

(Source: Mezmorize)

Build Date

« 00 08 02 !KONAMI »

This string, present at 0x11367 is written to the save file upon creation. When loading a save file, the game looks for the string to determine if save data exists.

Secret Characters

Two secret opponents can be unlocked after clearing the final stage, by using the following passwords:

Password	Character	Image
83771069	Kaiser Umiuma
19170603	Yugi Gonbutori