Despite some bugs and glitches, this game isn't that bad at all!
I mean, yes, there's a lot of bad stuff in this game: First of all, this game is obvious a beta, a broken game. The camera is awful, some levels have an awkward and dysfunctional design, the loadings time are pathetic (a loading can take 20 seconds for only a 2 second speech, then you have to wait another 20 secs...). There's also missed/ unreleased stuff in the game. At some point, the game recommends you to use your map when you're lost, but guess what, there's no map at all!! There's also a secret ending (not the final one) that became incomplete, so it wasn't released in the game, but it's hidden in the game disc. Also, there should be a rainbow gem, but, once more, it wasn't included in the game. But this game have a lot of good stuff!
This is the first game where Sonic is incredibly fast, the gameplay is kinda fun, the graphics are cool (even for 2013, except some scenario textures), the story is very good, some missions are interesting and the cutscenes are ok.
This game had to better, the camera is worst than/ bad as the original Sonic Adventure from 1999 and the gameplay could be better, but this game really gave me a really good time!