Blue Spheres: Start Sonic The Hedgehog about 18 to 21 times
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.
Knuckles In Sonic 2: Unlocked in the process of starting Sonic Spinball and Sonic 2 fifty times.
Ristar: Start all games (Sonic 1, 2, 3, Sonic And Knuckles, Sonic 3 And Knuckles, Knuckles In Sonic 2, etc.) fifty times.