And we got another Sonic prototype around and it is pretty different from the final. Other prototypes are Tails' Adventure - Review Copy and Sonic Labyrinth - Review Copy, but they are nearly final. The Sonic 2 GG AutoDemo has an internal date code of 1991-12-05, nine months before the final's date of 1992-09-05. People already hacked the Sonic 2 GG Auto Demo to make it playable, so check that "hack" out too! (There are lots of different stuff, no Tails around and it is pretty broken on some levels, spikes and springs actually work though). Google is your friend, since it is warez AFAIK.