Ok let me start by saying the game has a very interesting storyline which involves sonic going into the world of the arabian nights and return the pages to what they once where before the evil Erazor Djinn can destroy the book and leave it to take over Earth. Along the way sonic must gather seven 'world' rings, each sealed with it's own emotion. These rings act a lot like the seven chaos emeralds only they seem to be more powerful as it only takes three for sonic to transform into his new super form which was created especially for this game. Now onto the controls.
Okay, a situation arises during gameplay when sonic misses a bad guy. So you tilt the remote backwards to move backwards but because the camera doesn't adjust to this in the slightest, what you're left with is an annoying jolt as you accidentaly walk backwards into the baddie instead. Also there is a definite delay between the time when you move the remote side to side to make sonic move and his reaction. This isn't a big problem but you can definetely notice it.
At the beggining of the game Sonic takes what seems like forever to finally start moving his little hedgehog feet quickly enough to make it feel like a sonic game again, which is a little frustrating but still fun once he is up to speed. The new jumping technique can be quite useful aswell, as instead of jumping right away he charges it by skidding which slows him down long enough for you to get an idea of what your next move is. After a little gameplay sonic gains access to his soul gauge which gives him two cool new powers, speed break (which makes him run very fast and also kill any enemies he runs through) and time break (which lets you slow down the world so you can avoid difficult traps or get your bearings during a boss fight)
So a B, because the story is good, the speed is great and the new abilities give the game a new edge. but the backwards moving and the un-interesting movies lack that special oomph i look for in sonic games.