Sonic CD: The Time Stones and the Two Futures

Sonic CD’s time travel mechanic gave every act two additional versions: a Past and a Future that changed the visual design, music, and enemy population of each zone. The distinction between a Good Future and a Bad Future was determined by whether Sonic destroyed the Metal Sonic Projector and Robot Transporter hidden in each zone’s Past.

The Bad Futures are extraordinary art direction for a 1993 game — decayed, rusted, with dead vegetation and broken machinery overlaid on what the Good Future shows as pristine and verdant. The design team created two complete visual identities for every zone and hid the better one behind requirements the game explains poorly.

The Japanese and European soundtrack for Sonic CD — composed by Naofumi Hataya and Masafumi Ogata — and the American soundtrack by Spencer Nilsen are so different that they create essentially two different games. The Japanese version’s Past music is eerie and slow; the American Past music is ambient. The Japanese Future Bad music is frantic and distorted; the American version is calm and melancholic. CD has been released and re-released with debates about which version is canonical that have never been resolved.

A hidden image accessible via the sound test in the Japanese version shows Sonic and Amy with a message from the development team — a staff roll Easter egg that became one of the series’ most discussed hidden images, referenced in the official Sonic the Hedgehog 25th anniversary art book.