I personally didn't think the music was all that bad, but I digress.
At first, I had very little interest in this game, since it seemed to be little more than a straight rehash of Generations (which, as I've said in the past, is pretty overrated), where they're once again milking the Unleashed daytime engine, making Sonic the only playable character, and treating other characters as if they're insignificant just to please all the idiots who use Sonic's so-called "shitty friends" as a scapegoat for the past games supposedly being "terrible". Since there's actually a third playable character (which isn't Sonic for a change), that does throw that trend out the window just a tad.
However, I'm pretty mixed on the third character, mostly because I just don't understand Sonic Team's logic at all. They've avoided making other characters (including Tails and Knuckles, even) playable in almost every game in the past ten years out of fear of backlash from the purists and fanboys, and then when they actually do decide to go through with it again, they create a new character (which is most likely why they got said backlash in the first place) instead of using one of the established characters that they've been neglecting for so long. You'd think they would have done that first before adding a new character into the picture, but whatever.
Overall, I guess you can say that I'm mixed about the whole game in general. Even now, I'm still far more interested in Mania than I am in Forces.