Sonic the Hedgehog's cheat codes? I still remember level select and debug. Oh debugging was so fun on this. I remember that level select was UP, DOWN, LEFT, RIGHT, HOLD A, PRESS START. I remember it like the back of my hand. I also was able to combine the two codes to create debug / level select in one code. UP+C, DOWN+C, LEFT+C, RIGHT+C, HOLD A, PRESS START. Sonic the Hedgehog 2 had a bit more difficult cheat code, requiring sound test in the correct order.
I just miss playing on my Genesis, I'm stuck playing Sonic's Ultimate Genesis on Xbox360.
I still don't know why I can remember this? Am I a fanboy??