Reeves overshadows Carrey. Kidding, he does not, simply because he has less screen time (if you even count voice-over as such), and I just thought it would be a good pun, since Reeves voices over Shadow.
Puns aside, it's an ok movie. Others have pointed out as well, that this is essentially the same as previous one, but with Shadow and 2 Robotniks, so you should not expect anything special from the plot. In fact, it has at least 2 plot holes: why Shadow was allowed to roam that base at all, and why did they not just destroy the key, when they could?
Not like anyone is expecting very strong plot here anyway. I guess people come mostly for the action and humor. There are both. Action is... Ok, nothing particularly special or memorable. Humor... Also ok. I chuckled a few times, definitely liked a few nods to popular culture here and there, but will forget everything tomorrow.
So, in the end, I'd consider this a good way to spend the evening and go to sleep right after. And if you are a Sonic fan, you probably will be glad to know that there will be another sequel.
