Flicky — Play Dr. Robotnik's Mean Bean Machine 30 times.
Ristar — Play Blue Sphere, Knuckles in Sonic 2, Sonic 3 & Knuckles and Flicky 30 times each.
The Ooze — Play Sonic the Hedgehog, Sonic the Hedgehog 2,Sonic the Hedgehog 3, Sonic & Knuckles, Sonic 3D: Flickies' Island and Dr. Robotnik's Mean Bean Machine 20 times each, or have a Sonic Heroes save file on the memory card in Slot 1.
Comix Zone — Play any of the Mega Drive Sonic games 40 times, or have a Sonic Heroes save file on the memory card in Slot 1.
The following descriptions are quoted from the introduction screen of each game.
Sonic the Hedgehog (16-bit): Sonic the Hedgehog was the game where Sonic made his grand debut to the world. This exhilarating action game gave a special experience with its dizzying high speed sensation, and gave gamers their first glimpse of the original blue hedgehog who captured the hearts of millions. Needless to say, this was a huge hit. On the Japanese package, it even says "The Most Famous Hedgehog in the World!"
Sonic the Hedgehog 2 (16-bit): Released in 1992, this is still one of the most popular games in the series. Miles "Tails" Prower, a young fox, was introduced in this game. Together with Sonic, he fought against Dr. Eggman.
Sonic the Hedgehog 3: This is the third game in the series, released in 1994. The red echidna, Knuckles, was introduced in this game. Having been tricked by Dr. Eggman, Knuckles thinks that Sonic has come to steal the Chaos Emeralds. This is the beginning of the battle between Sonic and Knuckles, and this long story continues on through the spin-off game "Sonic & Knuckles."
Sonic & Knuckles: This game was released only 8 months after the release of Sonic 3. Knuckles, the red echidna, can glide through the air, climb walls and show off other unique moves. This game can be experienced from a totally different angle with Knuckles. Since the story line continues from Sonic 3, the difficulty is slightly higher.
Blue Sphere: Play through special stages by locking on "Sonic & Knuckles" with "Sonic the Hedgehog." Only special stages from Sonic 3 can be played with this method. To win these special stages, find a group of Blue Spheres and collect all the bordering Blue Spheres. Once you do this, all the Blue Spheres will turn into rings! Be careful though, if you touch any Red Spheres, the game is over.
Knuckles in Sonic 2: Play as Knuckles through "Sonic 2" when you lock on "Sonic & Knuckles" with "Sonic the Hedgehog 2".
Sonic 3 & Knuckles: Play through the "Sonic 3 Complete version" by locking on "Sonic & Knuckles" with "Sonic the Hedgehog 3". There are special events that must not be missed, which are only shown through this method. Also, a save feature is added to this game!
Sonic 3D Blast: This Sonic game is like no other in the series. Control Sonic from an isometric view point. Defeat the enemies and free the Flickies!
Note: The game's title differs with region (US: Sonic 3D Blast, Europe: Sonic 3D Flickies' Island), but gameplay is identical.
Sonic Spinball: Use Sonic as a pinball and get the Chaos Emeralds back from Dr. Eggman's fortress.
Dr. Robotnik's Mean Bean Machine: Remove the beans by stacking 4 of the same colored ones together. Attack your opponent by creating combos.
Flicky: Flicky is a Sega classic masterpiece. Many people may recognize the little birds, called Flickies, from various Sonic games. They were one of the helpless creatures trapped within Dr.Eggman's insidious robots that Sonic freed from captivity.
Sonic the Hedgehog (8-bit): Sonic's first "High-speed Action" game on the Game Gear. Use Sonic's blinding speed to defeat Dr. Eggman, who wants to get all the Chaos Emeralds!
Sonic Labyrinth: Sonic, now unable to run or jump due to the Speed-Down boots he's been forced to wear, must try to recover the Chaos Emeralds in Dr. Eggman's labyrinth by using his only remaining ability, the Rolling Dash!
Sonic Drift: Sonic and his friends race their high speed machines aiming to become the top Chaos Grand Prix winner!
Sonic Chaos: Tails now appears who can fly using his two tails. A new playable character, he doubles the fun of the game. Get those Chaos Emeralds back from Dr. Eggman!
Note: The game title differs with region (Japan: Sonic & Tails, US/Europe: Sonic Chaos, but gameplay is identical.
Sonic Blast: Now featuring Sonic and Knuckles! Knuckles offers new fun with his ability to glide and climb walls. A 3D Special Stage is also introduced. Now go to Silver Castle and recover the Chaos Emeralds from Dr. Eggman!
Note: The game title differs with region (Japan: G Sonic, US/Europe: Sonic Blast, but gameplay is identical.
Dr. Robotnik's Mean Bean Machine (8-bit): Play a classic puzzle game, Puyo Puyo, in the world of Sonic. Help the Beans before they become robots!
Bonus features
A mid-game saving feature was added. Bonus material includes high-resolution scans of the manuals of all MD/Genesis and Game Gear Sonic games, covers of the Archie Sonic the Hedgehog comic, official illustrations of all series characters (updated since the GameCube version to accommodate games released in the interim), and movies of the production process of Sonic Heroes from storyboard to finished game. Hints can be unlocked for each game by running them for 3 hours. The game doesn't need to be played, just opened. After 3 hours, the player should exit out and then re-enter the game.
2-player split screen is available for the Game Gear games Sonic Drift and Dr. Robotnik's Mean Bean Machine. This is activated by pressing on the second controller at any time while the games are running. Player 1's screen will be on the left, and player 2's screen will be on the right, and both players must select the respective 2-player mode option on their screens. Playing in multiplayer will disable the mid-game saving feature.
Pressing the right stick (PS2) or F1 (PC) during a game will toggle the size of the screen. This is most noticeable on the Game Gear games but will work on the Mega Drive games too.