If the player hits a Power Sneakers item box in any of the Sonic games, a higher-pitched version of the theme is played and not the usual sped up version. This is due to inaccurate emulation of the music, where instead of just the tempo increasing, the true speed -- and therefore pitch -- also increases.

Originally, the games Sonic Spinball, Sonic 3D Blast and Dr. Robotnik's Mean Bean Machine were to be included as part of the collection, however, they were cut from the game during development.

This would explain why sprites from Sonic Spinball and Sonic 3D Blast can be seen in the game's credits.