I've played this game for a few days now. I have to say I actually like it. (You can hate on me all you want.)
Once you get over the fact it has Sonic in it and think of it as just a platformer, it's pretty good. Very playable despite a few glitches that I've encountered myself. The story is flat and bland, though that can be said for most Sonic games as well. The fighting sections aren't as cool as the platforming sections, but it's much better than the werehog gameplay in Unleashed.
That said, I wouldn't recommend this game. Not at the current price. Bring it down to $29,99 / 24,99€ and it'll be worthy of recommendation. I don't have a score to give, if I had to compare this to other games like Lost World, if you liked that you're probably going to like Boom. I didn't like Lost World that much and that's how I feel about Boom during certain sections of the game. Overall, it's likeable though.
<- Clears the exits before they come and get me ->