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 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.

Blue Spheres: Start Sonic The Hedgehog and Sonic 3D Blast twenty times each.

Comix Zone: Have a saved game file from Sonic Heroes on your memory card.

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.

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.

The Ooze: Have a saved game file from Sonic Heroes on the Xbox hard drive. Alternately, this game is 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.