Its a great game so far, its surprisingly deep with plenty of side levels and unlocks. Clearly, this game is made for the sonic fans. Graphics look nice and clean and very smooth, although i get unexplainable slow downs at times. Poor optimisation i guess? But they dont occur frequently enough to hinder the overall experience of the game.
Im not a big sonic fan, but if you are you'll feel nostalgic as you run through the levels with their remixed soundtracks. Oh and getting to play as BOTH sonics on each level is a plus.