Designers High Scores
To view the designers high scores, press Right, Right, Up, Up, Down, Space at the title screen.
I'm Outa Here
If you let Sonic sit for three minutes without doing anything, he'll grow bored, say "I'm outa here!" and race off the screen, thus ending the game.
Press Up, Down, Down, Left, Right, Space at the title screen. Just like in the Sega version, you can choose any level, past, present, or future. However, if you warp or finish the level you will return to the title screen.
Sound Test and More
At the title screen, press Down, Down, Down, Left, Right, Space to call up a Sound Test menu. Special things will happen if you select the following sound combinations and press Start.
PCM12, DA11 Debug Mode
PCM07, DA07 Play special stages
PCM03, DA01 Displays artwork
PCM12, DA25 Human-Faced Sonic w/ Japanese Message
PCM04, DA21 Hercules Sonic
PCM11, DA09 Revenge of the Mutant Artwork
Enter the Sound Test screen, and enter 7's in all the boxes. When you play that sound a secret stage will appear.