Sonic is joined by old friends Tails, Knuckles and Amy (who first appeared in Sonic CD) and newcomers E-102 and Big the Cat. All 6 are playable and lead to different ending, adding a tremendous amount of replay value. In yet another stroke of genius, Yuji Naka has made the game playable for virtually any gamer by making the game easier with certain characters and more difficult with others. If you’re hardcore, Sonic and Tails will probably be right up your ally, but your younger brother will most likely prefer E-102. The ingenious A-life system, first introduced in NiGHTS, will also be implemented in Sonic Adventure, although it’s not clear in what fashion.