Zone Select: At the Title Screen, press Up, Down, Left, Right. When you hear the Ring Chime, hold "A" & press Start.
Slow Motion: At the Title Screen, press Up, "C", Down, "C", Left, "C", Right. While playing, Pause the game. "A"= Restart, "B"= Slow motion, "C"= Frame advance.
Slow Motion/Debug Mode: Enable Control Mode. Hold "A"&Start. When the game fades in, the score should be a double row of Hex Numbers. Debug controls are as follows: "B"= Turn into object. "A"= Change object. "C"= Place object on screen.
Demo Sonic Death: You can mess up Sonic during the Demos by pressing "A"+"B"+"C" at the same time. He will lose his place in the sequence, in some places even Die.
All 6 Chaos Emeralds: Enter the Zone Select code and go to the Special Stage. Get the emerald. When you get to the Score Screen, Reset the game. Repeat until you have all 6 Chaos Emeralds, then play the game. Don't forget to reset between emeralds, or you lose everything!