You need 50 Rings and then to jump into the Big Ring at the end to play a special stage. Try to get the Chaos Emerald. Try to get all 6 and finish the game. If you don't collect any emeralds, at the End, Dr.Eggman will stand on to of the words "Try Again" juggling the Chaos Emeralds. If you collect some Emeralds, Eggman will juggle just the one you didn't collect. If you collect all the Emeralds, he'll trounce the word "End" repeatedly. It's funny. And it's better than the Emerald Juggling.
During the demo, hold C. Sonic will crash into walls and get hit by enemies.
Use the level select cheat, and on the level select stage choose the special stage. Obtain the Chaos Emerald and once you have done so, soft reset the game.
Enter the level select cheat again and repeat this same process until you obtain all 7 Chaos Emeralds.
To pass Scrap Brain 3 in a very short amount of time, press the button at the beginning of the level, and jump over the bridge to go in the path below the bridge. Jump over all the pits. By the last pit, fall down, and go up the path on the right until you see the red jumper. The jumper brings you to the next level.
if you really need to beat a boss, just make sure that you have at least 1 coin. as long as you have one, you can not lose a guy, which gives you the advantage against the bosses.
In this level you have no rings so be careful.
Stand between 2 pillars. If robotnik appears, then smash him. The lasers will now come. Stand in the middle and jump when they are near you. Repeat this until he is defeated, then run after him. The next bit does not matter.
Smash into robotnik's ship and complete the game!
While the demo is playing hold A + B + C. Sonic will get confused, lose his place and possibly die.
To activate the level select on the title screen press:
up, down, left, right, A + Start. If you have done this correctly the level select screen will then be displayed.
The timing on pressing A + start together is important, they must be pressed at the same time otherwise the cheat won't activate.
At the menu screen press: UP C DOWN C LEFT C RIGHT C. You will hear a ding. Then hold down A and start. When the level begins you should have kept both A and start held down. Press B to verify yo have entered debug mode.