Sonic the Hedgehog 2
Sonic the Hedgehog 2 was weird in that cheat codes were entered by making specific choices in the sound test menu. Pick the right sounds and you’ll unlock the level select. Enter another code (find the details on our site!) and you’ll start the game with all kinds of weirdness. That’s the game’s debug mode! From there you can do all sorts of stuff, including enabling Super Sonic and designing your own levels.