Debug Mode in Sonic 3 & Knuckles (Sonic Mega Collection Plus, PS2)

The PS2 port in Sonic Mega Collection Plus does not include a Debug Mode. The only "hidden" menu accessible via code is the Level Select (sometimes called Stage Select).

Level Select Code (Title Screen)

1. At the "Press Start" screen, input: Up, Up, Down, Down, Up, Up, Up, Up (or Up, Down, Left, Right, A, B, C, Start — varies by region).
2. A sound confirms success.
3. Start game → Level Select menu appears.

What Level Select Does

• Jump to any zone/act.
• Choose character (Sonic, Tails, Knuckles, or Sonic & Tails).
• Does not grant: object placement, hitbox viewer, RAM watch, or physics tweaks (true Debug Mode features).

True Debug Mode

Exists only in the original Genesis/Mega Drive ROM (activated via level select + specific button combo). The PS2 emulation layer in Mega Collection Plus does not expose it.

For full Debug Mode, play the Genesis version via emulator (Kega Fusion, BlastEm) or the Sonic Origins compilation (which includes a "Debug Mode" toggle in the museum/extras menu).