Blue Sphere
Blue Sphere, known as Special Stage Mode in Sonic & Knuckles Collection, is an easter egg video game built into the Sonic & Knuckles cartridge for the Sega Mega Drive, accessible by attaching any Mega Drive game cartridge (other than Sonic the Hedgehog 2 or Sonic the Hedgehog 3) into the Sonic &...
- Developer: Sonic Team
- Publisher: Sega
- Released: 1994-10-18
- Genres: Platform, Arcade