Frustrating, disappointing, and generally broken.
Graphics: The environment looks alright, but the graphics and flow of everything do not mix well with the actual game play. The graphics could have used some work.
Music: Usually, music dosn't bother me, but the music in this one was a tad lame. It would have sounded better in a Pokemon game.
Controls: Terrible. There is no way to invert the x-axis, and certain attacks and actions don't function as they should and when they should.
Game play: It could be worse, but it would take some effort. Although in the game it appears you are running at high speeds, you never forget that you're still sitting on your couch, frustrated. You can play a clumsy and badly controlled Sonic where the camera constantly switches and -whether you want to or not- so do your controls. Tails is even worse, I don't know where the ridiculous idea of "dummy ring bombs" came from, but as you are using this lame attack, the camera does nothing and gives you not the slightest idea of where your enemies are or where to drop the bombs.
Bottom line: This game is severely frustrating and overall very little effort was put forth by Sega. I almost shed a tear thinking of what sonic used to be, from the Genesis to the Dreamcast, it was one of the only games that I knew was always going to be amazing.