Level Select:
At the title screen press up,down,left,right. Then, after you hear a ring chime, hold A and press start.

Debug Mode:
At the title screen press up,C,down,C,left,C,right. Then, after you hear a ring chime, hold A and press start. (You seem to have to do this twice, so after you enter the first time, press start and then A and the game will restart) While this is on, you cannot be killed by getting hit without rings.

These 2 codes can be used together and Debug mode even works in special stages.

If you know any other codes or tricks for this game, post them here.

This message was edited by Vitehite on Jan 23 2005.

Thanks for those

http://www.neoseeker.com/Games/cheats/GENESIS/sonic_the_hedgehog.html submit you cheats there. Infact I think I'll submit some cheats there.

there is one extra cheat

u can only use it in sonic mega collection and Plus version. by pressing Z 9 times and pressing up,down,left,then right before u go into the game. it not than much of a cheat though. it just lets u play the japanese version

whats the difference?

Slightly better graphics, and the "Spike Bug" is fixed.

Also, not really a cheat, but after defeating a boss, if you go to the right of the capsule and fall to the left as you jump on the button, you'll still be there as it explodes (Sonic will push to the right and run off).