I think you're learning from your mistakes though.  Sonic Rivals's visuals look sharp and using the trusty "3D objects with a 2D camera angle" trick is gold.  However, you really should just go ahead and make a real old fashioned 2D Sonic game out of it.  I don't want to race other players.  Racing other players in a Sonic game amounts to just holding down the "right" side of the control pad and occasionally jumping over a rock.  Give me those large worlds from Sonics past where I have to collect rings and speed through loops and collect Chaos Emeralds at my own pace.  I'm the eternal optimist, Sega.  I know one day you'll make me proud again.  This stubborn commitment to racing games where they don't quite belong isn't doing either of us any good though.

I could be wrong about this.  After all, I'm making a snap judgment based on some screenshots and a press release.  My cynicism comes from nearly a decade of sour Sonic projects.  I've seen what happens when you try to take Sonic out of his traditional platforming element.  I know what happens when you make a Sonic racing game.  I really hope you surprise me and that Sonic Rivals goes down in history as Sonic racing done right.  Considering past performance, however, let me just say that there's still time to overhaul Rivals and turn it into a proper adventure.  The racing part can stay as the usual tacked-on multiplayer mode if you want.  Just don't blow another opportunity to create a stellar Sonic game.  I may hold out hope forever, but not everyone is so patient.