Cheat Codes: Activate the following cheats by pressing the corresponding sequences of buttons at the specified screen:
Level select - At the title screen, press Up, Down, Left, Right at the title screen. Hold Y and press Start to select a starting level. Debug mode - Get a game over or complete the game in order to have the game reset. Then, press Up, A, Down, A, Left, A, Right, A at the title screen . Hold Y and press Start. Highlight a level and press Y to start Debug mode. Knuckles - At the title screen, press Up(3), Down(3), Left, Right, Left, Right at the title screen. Then, hold Y and press Start.
Bonus points: To receive 50,000 bonus points, complete Green Hill Zone 1-1 or 1-2 in under 29 seconds.
Unlimited lives: Collect the extra life at the very bottom of Green Hill Zone - Act 3. Accumulate 100 rings to obtain another extra life. Collect a third extra life located at the top of the loop-the-loop. Intentionally lose a life and repeat the process.
Special Zone entrance: You can almost always have the Special Zone entrance open (the giant ring next to the sign at the end of level Acts 1 and 2) by not losing your rings. If you do lose your rings, when you pass a checkpoint, intentionally die, then continue through the level without losing any rings. This works about 80% of the time.
Collect 50 rings and finish the stage. There will be a giant ring.
"Sonic Posts" 10,000 point locations: Green Hill Zone 1 - When Sonic passes the zone, make sure to pass his body all over the last tree. A "10,000" bonus point is hidden there. Green Hill Zone 2 - When Sonic passes this zone, make sure to pass in between the second and third palm tree. The bonus point worth "10,000" is there. Marble Zone 1 - When you view the message "SONIC HAS PASSED ACT 1", you should noticed three columns. To the right of the third column, pass all over the little area to get the "10,000" point bonus. In order for this to happen, you should use jump as much as possible to get him to reach the point bonus. Marble Zone 2 - When you view the message "SONIC HAS PASSED ACT 2", pass his body all over the right side of the screen. You should get the "10,000" point bonus. In order for this to happen, you should use jump button as much as possible to get him to reach the point bonus. Spring Yard Zone 1 - The next "10,000" bonus point is directly above the sign. Spring Yard Zone 2 - The "10,000" bonus point is just above the blue post prior to the sign. It is closest to the left side of the screen. Labyrinth Zone 1 - The "10,000" bonus point is on the ceiling nearest the right side of the screen. Labyrinth Zone 2 - Although there is a point amount near the zone's sign post, that is not the "10,000" bonus point. The "10,000" bonus point is on the top right hand corner of the screen. Star Light Zone 1 - The "10,000" bonus point is slightly above the top right hand corner of the screen. When you hit it, you can just barely see the bottom left hand corner of the point when you return to the ground. Star Light Zone 2 - The "10,000" can be obtained by having Sonic jump "on top of" the second lamp post that can be viewed from the screen. When you return to the ground, you cannot see the point. Scrap Brain Zone 1 - Under the ground, you will see a series of pipes that seems to go in this pattern - "l n l". The "10,000" bonus point is above the first "l" (pipe). This might be complicated to get. Scrap Brain Zone 2 - No points here.
Note: There are no points in Zone 3 of any of the Zones.
Level select: Go to any pulley in the first level and press Left(3), Right(3), Up(3). The sound of a ring being collected will confirm correct code entry. Get a game over to reset the game. Then, hold Y and press Start at the title screen to display a level selection screen.
Sonic And Knuckles 2: Level select: Press Up(3), Down(3), Left, Right, Left, Right, then hold Y and press Start at the main menu.
Sonic And Knuckles 3: Debug mode: Successfully complete the game. Select Zone 1 (Angel Island) on your saved game file. Hang off the first swinging rope, then press Left(3), Right(3), Up(3). The sound of a ring being collected will confirm correct code entry. Intentionally lose your lives until the game ends. Do not use any continues. Wait for the timer to drop to zero. Return to the same saved game file and select Act 7 (Mushroom Hill). Go to the first pulley past the enemy that throws mushrooms and the Speed Shoes box. Note: Knuckles must back track on Sonic's path once you get to where they merge. While hanging on pulley, press Left(3), Right(3), Up(3). The sound of a ring being collected will confirm correct code entry. Intentionally lose your life, then hold Y until the level reloads. Press B to complete the code. To change levels, get another game over and hold Y while a level loads.
Tails name changed to Miles: Press Up(3), Down(3), Up at the title screen. Tails' name will be changed to "Miles". Note: The opposite will occur in the Japanese version of the game.
Level editor: Enable the "Debug mode" code. During game play, press the button configured as "B" on the Genesis. Sonic should become an object somewhere on the level. Press the button configured as "C". You can "paste" that object in the level. Press the button configured as "B" again to resume game play. Press the button configured as "A" on the Genesis while editing the level to change the object. You can also move the object in the air, etc. to truly make your own challenge. Also, you can move across obstacles and turn back to Sonic to cut points in the level.
Super Sonic: Enable the "Level select" code. Use the sound test selection on the options screen. Choose sounds 4, 1, 2, 6 (in that order). Start a stage, collect 50 rings, then jump to transform into Super Sonic.
Super Tails and Super Sonic: Enable the "Level select", "Debug", and "All Chaos Emeralds" codes. Then, start any level and get 50 rings. You can use the "Turn into a ring and give them to Tails" trick. When you turn into Super Sonic, use debug mode to turn into a television. It should be a "switch" television from versus mode when you place it. If you break it, you will see a brief glitch, which will not effect the game. You will see everything return, with one small difference. You will still have Super Sonic's appearance, but he plays like Sonic with regular speed, normal jumps, etc. Tails, however, has Super Sonic's power and cannot be "hurt". This will last for however many rings you had when you hit the television; start when you have at least 100 rings. Then, hurt yourself so that you lose all your rings and you will lose Super Sonic's appearance. Then, use the trick to get fifty rings again and jump. You should now have Super Sonic and Super Tails.
Mega Sonic: Collect fifty rings and jump after becoming Hyper Sonic for even more speed and higher jumps.
Unlimited speed shoes: Begin game play in two player vs. mode and hit as many item boxes as possible until you get the speed shoes. Then, intentionally 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 will now have the speed shoes in effect for the rest of the stage.
Unlimited lives: Enable the "Level select", "Super Sonic", and "Debug mode" codes and enter any stage. Get fifty rings and turn into Super Sonic. Change Sonic into the television monitor. 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, and they will be destroyed because Tails is invincible. You should get lots of points, which add up to extra lives.
Super Sonic sign: Get all of the Chaos Emeralds and transform into Super Sonic. Try to have at least fifty rings when you finish the level. After completing the level, run off screen and wait until the end-of-level sign shows Sonic. When it does, transform into Super Sonic. The sign will show Super Sonic for one second, then show blue Sonic again.
Starry Super Sonic: Get all the Chaos Emeralds and collect fifty rings, but do not transform into Super Sonic yet. 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 blue Sonic. Note: This does not improve Super Sonic's performance.
Stronger Super Sonic: Enable the "All emeralds", "Level select", and "Debug mode" codes. Go to Oil Ocean (either act). Become Super Sonic, then stand on one of the green/yellow colored cylinders. Jump on it, but as soon as you hear it break, go into debug mode. You should be thrust upward, even in your debug state. Then as soon as you regain traction, exit debug mode. You should now be able to jump twice as high and fast. Bonus points: For extra points, pass any zone in a certain amount of time. For the best bonus, enter the "Debug mode" code. The clock will stop and you will always score a 50,000 bonus.
Wing Fortress shortcut: In Wing Fortress, move with some rings as far to the right as possible without climbing. When blades appear to block your way, hit them. As soon as you are invincible, walk through them. Jump on the platforms to the right and half the level will be completed.
Flames follow Sonic: Enable the "Debug mode" code. You can also enable the "Super Sonic" code, if desired. Go to Death Egg Zone and defeat the two bosses. 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. Go back to where you battled the egg robot. Flames should follow you where ever you go.