Original Sega Genesis cheats work, using (PS2), B/X (Xbox), or PC keys:
For full walkthroughs, maps, and tips, see resources on GameFAQs or IGN. Original, in-game manual scans are also available via the main menu. Sonic Mega Collection Plus – Guides and FAQs - GameFAQs Sonic Mega Collection Plus
is a compilation of classic SEGA titles originally released for PlayStation 2, Xbox, and PC. This guide covers how to unlock hidden games and use classic cheats. Unlocking Hidden Games Original Sega Genesis cheats work, using (PS2), B/X
In Sound Test, play: 01, 09, 09, 02, 01, 01, 02, 04. Sonic 2 (Emeralds): In Sound Test, play: 01, 01, 02, 04. This guide covers how to unlock hidden games
Up, Down, Left, Right (chime), then hold Square/X and Start.
Play Blue Sphere , Knuckles in Sonic 2 , Sonic 3 & Knuckles , and Flicky 30 times each.
Unlock additional games by opening and exiting specific titles multiple times, returning to the main menu each time: Play Sonic 1 and Sonic 3D Blast 20 times.