Level Select
On the title screen, press U,D,L,R, then A and Start together.
Debug mode
On the title screen, press U,C,D,C,L,C,R,C and then hold A and Start together until Sonic appears.Once the code has been activated, pressing B will turn Sonic into an object (press B again to turn back into Sonic), once Sonic is an object, press A to cycle through the objects and C to place them.
Sonic 2
Level Select Go to the Options menu. On the Sound Test play sounds 19, 65, 09, 17 in that order. Now press Start. On the title screen, press and hold A and Start together until the Level Select appears.
Debug Go to the Level Select screen. On it's Sound Test, play sounds 01, 09, 09, 02, 01, 01, 02, 04 in that order. Highlight the level you want to play and then hold A and Start until Sonic and Tails appear. (the code works the same as Sonic 1)
Super Sonic Go to the Level Select. On it's Sound Test play sounds 04, 01, 02, 06 in that order. Now highlight the level you wish to play and hold A and Start together. To turn into Super sonic, collect 50 or more rings and jump.
Turn into Ashura (the green Sonic) (Please note this code only works in Emerald Hill Zone - once this zone has finished, Sonic will turn back to normal).
Go to the Level Select and activate the Debug code. Highlight Emerald Hill zone Act 1 or 2 (doesn't matter which).
Hold A and Start until Sonic and Tails appear. Turn Sonic into an object. Keep pressing A until he turns into an object which seems to be invisible. Now move to the first waterfall you find. Place as many of the object onto the waterfall as you can. Eventually, Sonic's lives counter will turn green. Turn back into Sonic and run out the waterfall. He should now be Ashura.
Access the unfinished Hidden Palace zone (requires a Game Genie) Enter the code ACLA-ATD4 into the Game Genie. Go to the Level Select and activate the Debug code. Now highlight Death Egg zone, and hold A and Start until Sonic and Tails appear. There are no floors in this zone so you will need Debug. All the objects in Debug are those of Oil Ocean
zone, as the Hidden Palace graphics are not in the final game.
Sonic 3
Level Select This is very tricky to do. After the sega logo appears and Sonic jumps towards you, quickly press U,U,D,D,U,U,U,U,U. If you do it quick enough, you will hear a chime. On the title srenn press D twice and an option called "Sound Test" will appear. Select this option to go to the Level Select screen.
Debug Go to the Level Select. Simply highlight the level you wish to play, and hold A and Start together until your chosen character appears.
Super Sonic Super sonic:
Go to the Level Select. Highlight your level and hold A and Start together until Sonic appears.
Cycle through the objects until you find a monitor with an "S" on it. Place this and break it open. Do a double-jump to transform into Super Sonic.
