Sonic The Hedgehog

Enable the "Level select" code. Select the "Bonus level" option on the level selection screen. Obtain the Chaos Emerald, reset the game, and repeat the process until all of them are in your possession. Allow the game to continue after obtaining the last Chaos Emerald to start in the Green Hill Zone.

Note: When you collect all of the Emeralds, you will not become Super Sonic, but you will be practically invincible. Try the following. When you have no rings, get attacked by something. Sonic will fall back (as if he had a shield on him), but he will not die. However, Sonic will die if he falls off of the edge of something, sinks underwater, etc.

Complete Green Hill Zone 1-1 or 1-2 in 29 seconds or less to receive 50,000 bonus points.

At title screen type in :up,A,,down, A,left, A ,right ,A then A,start. This is a special level select,, it also allows you to hear the sounds and music.

At title screen type in :up,A,,down, A,left, A ,right ,A then A,start. This is a special level select,, it also allows you to hear the sounds and music.

For extra points, pass any zone in a certain amount of time. For the best bonus, enter the Debug
Mode code. The clock will freeze and you'll always score a 50,000 bonus!

There is a code called control mode, which is required before activating this code.

To activate control mode, press UP, C, DOWN, C, LEFT, C, RIGHT, C at the title screen, but before pressing start to begin the game, press and hold A as you hit start. Now, rather than just being in control mode, you can enable config mode by pressing button B.

Sonic will morph into a ring, and the arrows can move him anywhere, even in the air, or through obstacles such as walls, floors, or even ceilings {GREAT FOR TELEPORTING!}.

You can change the item Sonic appears as by hitting A while in config mode. Button B makes Sonic normal again, and button C will place the sprite that you have selected for Sonic to appear as. For example, you press B, and Sonic becomes a ring, press C to make a ring appear exactly where the ring icon is.

WARNING!: This will distort several different things, such as the score, time, and other various icons throughout the game such as the finish sign at the end of the first two acts of each zone that spins when Sonic shoots past them, and the small score icons that appear whenever Sonic jumps high enough after finishing a level. That is all I have noticed in my time playing the game, but there could be more out there yet. The game is still quite playable this way, so it should not hurt you.

Note: This code is for the Japanese version.
At the title screen, press Up, C, Down, C, Down, C, Down, C, Left, C, Right. You'll hear a ring sound. Start the game when holding A to be in Config mode that the Score and Time are distorted. Press B to enable Config mode, that Sonic morphs into a ring. Press A to switch through different items, Press C to place the sprite, hold A and press C to go backwards on selecting items, move around with the D-Pad, or Press B to morph back to Sonic.

While the demo is playing, hold A + B + C. Sonic will get confused, lose his place, and possibly die.

Enable the "Debug mode" code. Press B when Sonic is running with the animals at the end, then turn back into Sonic. You can nowcontrol yourself.

At the title screen press up c down c left c right.start the game.then,when you press pause then a,the game will restart.press c the game will move one frame,press b,the game will be in slow motion!