How to Unlock Debug Mode Unfortunately, the first time you play Sonic Mania, Debug Mode will not be unlocked. Doing so requires that you play the game and complete Blue Sphere stages.

Basically what I'm saying is - Debug mode is in, you filthy cheats. There's also a bunch of other Sonic Mania cheats and unlockables for Mania Mode in both the original release and Plus.

(Sonic 3) Unlockable: Mecha Sonic and Tails Use the Debug Mode code in Launch Base act 2. Beat the game. When Sonic or Tails jumps towards you, activate Debug Mode and get out of it immediately.