Tails name change:
At the title screen, press Up(3), Down(3), Up . A sound confirms correct code entry and Tails’ name will be changed to “Miles”. Note: The opposite occurs in the Japanese version of the game.
Level editor:
First, enable the “Debug mode” code. During game play, press the button configured as “B” on the Genesis and Sonic should become an object somewhere on the level. Press the button configured as “C” to”paste” that object in the level. To resume game play, the button configured as “B”. To change the object, press the button configured as “A” on the Genesis while editing the level. You can also move the object in the air, etc. to truly make your own areas. You can also move across obstacles and turn back to Sonic to cut points in the level.
Play as Super Sonic:
Enable the “Level select” code and select the sound test selection on the options screen. Choose sounds 4, 1, 2, 6 (in that order), start a stage, then collect 50 rings. Jump to transform into Super Sonic.
Play as Mega Sonic:
To play as Mega Sonic, collect fifty rings and jump after becoming Hyper Sonic for even more speed and higher jumps.
Unlimited speed shoes hint:
In two player vs. mode, hit as many item boxes as possible until you get the speed shoes. Then, lose your life while you have them (getting squashed is the easiest way). You will return to the start of the level or the last Star Post that you hit, but you should still have the speed shoes in effect for the rest of the stage.
Unlimited lives hint:
Enable the “Level select”, “Super Sonic”, and “Debug mode”. On any stage, get fifty rings and turn into Super Sonic. Change Sonic into the television monitor, then change Sonic back and have him jump to turn into Super Sonic. Jump on the television monitor to have Tails become invincible, then turn into an enemy and put it right on tails while he is invincible. Continuously place the robots there, which will be destroyed because Tails is invincible. You will get tons of points, which add up to extra lives.
Super Sonic sign:
After completing a level, run off screen and wait for the end-of-level sign shows Sonic. When it does, transform into Super Sonic and the sign will show Super Sonic for one second, then show blue Sonic again.
Starry Super Sonic:
Find an invincibility monitor and spin (do not jump) into it, then transform into Super Sonic. If done correctly, the stars will surround Super Sonic until he runs out of rings and transforms back into regular Sonic.
Stronger Super Sonic:
Enable the “All emeralds”, “Level select”, and “Debug mode” codes, then go to Oil Ocean (either act). Become Super Sonic and stand on one of the green/yellow colored cylinders. Jump on it and as soon as you hear it break, go into debug mode. You should be thrust upward, even in your debug state. As soon as you regain traction, exit debug mode to be able to jump twice as high and fast.
Wing Fortress shortcut:
In Wing Fortress, collect some rings and move as far to the right as possible without climbing. When blades try to block your way, hit them. As soon as you are invincible, walk through them, then ump on the platforms to the right and half the level will be completed.
Flames follow Sonic:
Enable the “Debug mode” code, as well as the “Super Sonic” code if desired. Go to Death Egg Zone and when you defeat the giant egg robot, turn into a ring instead of running all the way out. Go into the area where flames appear, then go back to where you battled the egg robot. Flames should follow Sonic where ever he goes.
Trophies:
Bronze trophies
Emerald Hill – Clear the Emerald Hill Zone 1.
Fast Emerald – Beat Emerald Hill Zone 1 in under 35 seconds in single-player or co-op mode.
Fast Chemical – Beat Chemcial Plant Zone 1 in under 45 seconds.
Casino – Get to the Casino Night Zone.
Chaos Emerald – Get one Chaos Emerald.
All Multiplayer – Play all four multiplayer zones.
Online Racer – Win 10 versus zones in online play.
Win – Complete the game.
Silver trophies
Super Sonic – Become Super Sonic.
Extended Super – Stay in Super Sonic mode for one minute.
Conquering Time – Beat the game in under an hour.
Gold trophy
Chaos Master – Get all the Chaos Emeralds.