Start Sonic The Hedgehog and Sonic 3D Blast twenty times each.
Comix Zone (Japanese version)
Select manual mode, then press Z(3), Up(3), Down(3), L, R, Z. A sound will confirm correct code entry.
Debug - S3K
Start a 1-player game on AIZ and grab a swing.While swinging, press left left left right right right up up up. You will hear a ring sound if entered correctly. Then pause and press A to return to the title screen. Press down twice to highlight the sound test you unlocked and press start. Select Mushroom Hill and do the same thing on the first thing you can hang on to (like the swing vines in AIZ). Do the same 3 left 3 right 3 up pause and press A. Go to the sound test and simply hold down A while selecting a level. Also while on level select, press C to change character. 00 = Sonic & Tails 01 = Sonic 02 = Tails 03 = Knuckles.
Debug Mode
There are 3 games that use Debug Mode. Sonics 1, 2, and 3. For Sonic 1, press X, X, up, down, left, right. You should hear a chime to confirm the code. Now hold A and press Start. Hold A until Sonic appears. For Sonic 2, play sounds 1, 9, 9, 2, 1, 1, 2, then play 4. (sometimes you might need to do it 2 times in a row) You'll also hear a chime for the code to be right. Now hold A and press Start until the stage begins. (you must use the Stage Select for this code to work)
For Sonic 3, use the Stage Select, highlight a stage and hold A and press Start. After you do one of these codes, you can do one of the following things.
B = change into an item
A = change into a different item
B (again) = change back into Sonic
X = put item on the screen
Tips:
#1: In Sonic 1, you are invincible using Debug Mode
#2: Using Debug Mode on Sonic 2, you can put a lot of rings on the screen, you can turn into Super Sonic very easily.
#3: You can usually change into a big 'glitched' thing. If you place it on the screen, there should be a paddle on top. Jump on it and you automatically pass the stage.
Doctor Robotnik's Mean Bean Machine
Dr. Robotnik's Mean Bean Machine (Easy)
Red, Red, Red, Has Bean - Level 2
Clear, Purple, Clear, Green - Level 3
Red, Clear, Has Bean, Yellow - Level 4
Clear, Blue, Blue, Purple - Level 5
Clear, Red, Clear, Purple - Level 6
Purple, Yellow, Red, Blue - Level 7
Yellow, Green, Has Bean, Blue - Level 8
Yellow, Purple, Has Bean, Blue - Level 9
Red, Yellow, Clear, Has Bean - Level 10
Green, Purple, Blue, Clear - Level 11
Red, Has Bean, Has Bean, Yellow - Level 12
Yellow, Has Bean, Blue, Blue - Level 13
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Dr. Robotnik's Mean Bean Machine (Normal)
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Has Bean, Red, Yellow, Clear - Level 10
Clear, Red, Red, Blue - Level 11
Green, Green, Clear, Yellow - Level 12
Purple, Yellow, Has Bean, Clear - Level 13
Has Bean, Clear, Yellow, Yellow - Level 2
Blue, Clear, Red, Yellow - Level 3
Yellow, Blue, Clear, Purple - Level 4
Has Bean, Green, Blue, Yellow - Level 5
Green, Purple, Purple, Yellow - Level 6
Purple, Blue, Green, Has Bean - Level 7
Green, Has Bean, Clear, Yellow - Level 8
Blue, Purple, Has Bean, Has Bean - Level 9
Dr. Robotnik's Mean Bean Machine (Hard)
Green, Clear, Yellow, Yellow - Level 2
Yellow, Clear, Purple, Clear - Level 3
Blue, Green, Clear, Blue - Level 4
Red, Purple, Green, Green - Level 5
Yellow, Yellow, Clear, Green - Level 6
Purple, Clear, Blue, Blue - Level 7
Clear, Yellow, Has Bean, Yellow - Level 8
Purple, Blue, Blue, Green - Level 9
Clear, Green, Red, Yellow - Level 10
Blue, Yellow, Yellow, Has Bean - Level 11
Green, Clear, Clear, Blue - Level 12
Has Bean, Clear, Purple, Has Bean - Level 13
Dr. Robotnik's Mean Bean Machine (Hardest)
Blue, Blue, Green, Yellow - Level 2
Green, Yellow, Green, Clear - Level 3
Purple, Purple, Red, Has Bean - Level 4
Green, Red, Purple, Blue - Level 5
Blue, Purple, Green, Yellow - Level 6
Blue, Purple, Green, Has Bean - Level 7
Clear, Purple, Has Bean, Yellow - Level 8
Purple, Green, Has Bean, Clear - Level 9
Green, Blue, Yellow, Has Bean - Level 10
Green, Purple, Has Bean, Red - Level 11
Red, Green, Has Bean, Blue - Level 12
Red, Red, Clear, Yellow - Level 13
Flicky
Start Dr. Robotnic's Mean Bean Machine before reaching 50 times. Alternately, have a memory card in slot A with a saved game from another Sega game.
Knuckles In Sonic 2
Unlocked in the process of starting Sonic Spinball and Sonic 2 fifty times.
Ristar
Start the following games fifty times: Sonic The Hedgehog, Sonic The Hedgehog 2, Sonic The Hedgehog 3, Sonic And Knuckles, Sonic 2 And Knuckles, Sonic 3 And Knuckles, Sonic 3-D Blast, Sonic Spinball; and start Blue Spheres 30 to 40 times.
Ristar codes
Code - Effect
XXXXXX - Cancel all codes
MUSEUM - Fight only bosses
ILOVEU - Level select
MIEMIE - See hidden items
SUPER - Super hard mode
DOFEEL - Time attack
MAGURO - Tone deaf sounds
SUPERB - Very hard difficulty
Sonic 1 Debug Mode
First go to the Sonic 1 title screen and press Up, X, Down, X, Left, X, Right, Up, X, Down, X, Left, X, Right, X. Now HOLD B and press Start. Now when the game starts press A to go to debug mode.
Sonic 1 Pick Level & Sound Test
First go to the Sonic 1 title screen and press Up, Down, Left, Right. Now hold B to pick a level & get sound test.
Sonic 2 - Be Super Sonic
After you've done the Pick Level code/cheat go to the Sound test screen and play sounds 04, 01, 02, 06. Now collect 50 rings and jump to be Super Sonic.
Sonic 2 - Super Sonic's Abilities
When you become Super Sonic, you achieve Super- jump, Super-speed, Super-spin dash and invincibility. (Note: Super Sonic uses rings, so be careful of your ring total)
Sonic 2 Debug Mode
First go to the Sonic 2 Sound Test screen and play sounds 01, 09, 09, 02, 01, 01, 02, 04. Now at the sound test screen hold B and pick a level and Start.
Sonic 2 Pick Level
First go to the Sonic 2 Sound Test screen and play sounds 19, 65, 09, 17. Now hold X and press START. Now on the title screen hold B and press START.
Sonic 2: Blue Invincibility
As Sonic & Tails, use the Super Sonic & Debug codes and go to any level. Then press B to enter Debug mode and spawn a 'TV thing'. Turn into Super Sonic and hit the 'TV thing'. After the blank screen appears, Tails should be invincible with stars flying around him. When Sonic turns back to normal, Tails' invincibility stars will then have a blue tint. Turn back into Super Sonic and the stars will become white again.
Sonic 2-Rainbow Sonic
After you do the Super Sonic code, (Sonic 2-Super Sonic {Real Way} Cheat), collect 50 rings and jump, (before you do this, use the Sonic 2-Debug Mode cheat), press Start, and tap B repeatedly. You should see Sonic changing colors.
Note #1: Sonic changes in this order: pink, blue, then yellow.
Note #2: If your timing is right, Sonic's colors will change to white on the front and black on the back (before he turns pink in note #1).
Sonic 2-Super Sonic {Real Way}
First go to Options. Then play these sounds from Sound Test in this order: 19, 65, 9, 17. When the last sound starts you will hear the sound of 'when you collect a ring'. Go back to the Title Screen by pressing Start. Now, when you highlight 1 Player, hold A and press Start. You should go to Level Select. There should be a Sound Test there too. Play these sounds in this order: 4, 1, 2, 6. When Sound 6 starts, instead of hearing the real sound, you'll hear a sound when you collect a Chaos Emerald. Finally pick a level, collect 50 rings and jump to be Super Sonic! {Note this will not work on Sky Chase, the other level using the airplane or playing as Tails.}
Sonic 3 - Debug Mode
Go to the Stage Select screen and hold button B. Then pick a level and start.
Sonic 3 - Get Extra Stage
After doing the Pick Level code/cheat, go to the Sound test screen and play sounds 01, 03, 05, 07. Now highlight Special Stage 2 and hold B and press START.
Sonic 3 - Pick Level
As you hear Sega spoken but BEFORE the main menu appears press: Up, Up, Down, Up, Up, Up. Then at the title screen press Up to get Stage select and Sound Test.
Sonic 3 & Knuckles: Glich Galore
First, use the level select code and go to Doomsday 1 with Knuckles and beat that level and you will see 2 Master Emeraids and more.
Sonic 3 And Knuckles:
Unlocked sometime in the process of starting Sonic 1, Sonic 3, Sonic And Knuckles, and Sonic 3-D Blast fifty times.
Sonic and Knuckles - Level select
Start a game with Sonic and run over to the Madmole near the Super Shoes power-up. Directly to the right of the Madmole is a pulley mechanism that takes you to the next level above by pushing Down on it. Instead of pushing down, push the Left, Left, Left, Right, Right, Right, Up, Up, Up. Now press Start to pause the game and press B. You will be sent back to the main screen. When you can select between Sonic and Knuckles, hold B and press Start for a level select.
Sonic The Hedgehog - Cheat Mode
At the Sonic The Hedgehog title screen, press Up, Down, Left, Right. Hold B for level select and sound test.
Sonic The Hedgehog - Debug mode
At the Sonic The Hedgehog title screen, press Up, X, Down, X, Left, X, Right, Up, X, Down, X, Left, X, Right, X, Now hold B and press Start. Press A to enter debug mode.
Stop Time in Sonic 2
Pause the game and hold A for the rest of the stage to play without time passing. Press X to jump and spin dash while holding A. You will move without time passing, but the enimies will still move. To stop the game just relese A.
The Ooze (Japanese version)
Select options mode, then press Up, L, Down, R, Up, Z, Down, L, Up, R, Down, Z. A sound will confirm correct code entry.
Unlocking hidden games
When you initiate Sonic The Hedgehog 1, 2, 3, Sonic And Knuckles, Sonic 3D blast, Dr. Robotnic's Mean Bean Machine, or Sonic Spinball, the screen states that it is logging the game data. That indicates the game is logging in that you have
initiated that game once. After initiating a game fifty times, it no longer shows that game-logging screen. It stops the logging sequence screen from ever starting a game again and from then on, just starts the Genesis program itself. To unlock a hidden game, you must start a particular Mega Collection game fifty times, continually pressing Z to exit it, then enter into the game repeatedly. Some hidden games do not necessarily require that you start up fifty times, but you eventually need to do so to unlock all the hidden games.