Don't get me wrong, this game is bad. The story was horrible, Shadow's section was repetitive and annoying, Almost every character in the game was an idiot (exceptions being Eggman and maybe Elise), there's way too much slow-down, and those loading times need to DIE IN A HOLE!!!!
However, there are some parts of the game that I really enjoyed. Silver's section was tolerable and very creative, And Sonic's section is really fun and is a guilty pleasure of mine.
In short, I'm not saying that the game is good, but it may be worth looking into.
This game is have very wacky controls, game play feels as though its a beta game, and story-line is not my cup of tea. The reason why I say try the game out is because if you have patience for the controls and storyline then you will find the game durable, but nothing like Sonic Adventure or Sonic Adventure 2.