Metamor Jupiter

Metamor Jupiter
Developer: Flight-Plan Publisher: NEC Home Electronics Platform: TurboGrafx-CD Released in JP: January 22, 1993 This game has a hidden level select.

Level Skip

This requires an emulator or, if playing on real hardware, a Pad that has been disassembled or modified to allow pressing opposite D-Pad directions simultaneously. Pause during gameplay and press Up+Down, II, I, Up+Down, II, I, Left+Right, II, I, Left+Right, II, I, Up+Down, II, I, Up+Down, II, I, Up+Down, II, Left+Right, I, then unpause. If entered correctly, the current level will be skipped.

Alternatively, holding Select while entering the above code will instead make the ship invincible against enemy bullets.

(Source: yamada_arthur)