lue 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 & Knuckles lock-on port. Blue Sphere is a collection of Special Stages in the same style and engine of those featured in Sonic the Hedgehog 3 and Sonic & Knuckles. If the cartridge that is locked on to Sonic & Knuckles is the original Sonic the Hedgehog (Sonic Classics, the Nick Arcade and Simon Wai prototype versions of Sonic the Hedgehog 2 will also work), then the full game of Blue Sphere is accessed with all stages. Most other cartridges will allow the player to access only a single stage of the game, based on the cartridge's ROM header and the stage's code in the full Blue Sphere game. Some cartridges with particularly large ROM file sizes (including Phantasy Star IV: The End of the Millennium and Super Street Fighter II: The New Challengers) will not load Blue Sphere, but will instead boot Sonic & Knuckles as normal. Locking on Sonic & Knuckles to another copy of Sonic & Knuckles will also load the game normally.
Blue Sphere
Genesis · 1994 · NTSC-U · Platform
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Live listings
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What it's actually worth
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No verified comparable sales in window. Real comp data integration (Heritage / Goldin / eBay Insights) ships V15.22+.
No verified comparable sales in window. Real comp data integration (Heritage / Goldin / eBay Insights) ships V15.22+.
No verified comparable sales in window. Real comp data integration (Heritage / Goldin / eBay Insights) ships V15.22+.
Why collectors care
The cultural context, the production lineage, the place this artifact holds in its console's history.
- First print documented
- No
- Regional / language names
- Special Stage Mode · Blue Spheres
Is what you're holding real
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Production reference
No production variants are documented for this title yet. The identifying marks below cover the title's first-print and reprint signals across all tiers.
Production reference
No production variants documented for this title yet. Identification reads against the title's known print signals across all tiers.
No documented marks for this tier yet.
No documented marks for this tier yet.
No documented marks for this tier yet.
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