Valis II (TurboGrafx-CD)

Valis II
Developer: Telenet Japan Publishers: Laser Soft (JP), NEC Home Electronics (US) Platform: TurboGrafx-CD Released in JP: June 23, 1989 Released in US: 1990 This game has debugging material. This game has a hidden sound test.

Debug Menu

At the title screen, press Up, I, Select, II, Down, Run. If done right, you'll be taken to a debug menu featuring a cutscene viewer, sound test, and color test.

Debug Mode

A second debug mode also exists in the game. To access it, hold II and pause during gameplay. Release II and press Up, Right, Down, Left, II, II, I, I, I, Select. "PAUSE" will change to "DEBUG" (pictured above) to confirm correct entry, and the following functions will be available:

When Paused

Button(s)	Function
Select	Toggle weapon.
II	Toggle special item.
Up + I	Levels up weapon.
Down + I	Increases speed.
Left + I	Increases maximum number of lives.
Right + I	Raises defense.
Select + I	Increases number of lives remaining.

When Unpaused

Button(s)	Function
Select	Fully restores health.
Up + Select	In a level, skips to the level's boss. In a boss fight, skips to the next level.

(Source: yamada_arthur)