Okay, so I actually just bought this game a couple of days ago. (Been waiting for a price-drop.) I got to say it has exceeded my expectations so far, I knew it would be decent or good because I've been following it since it was announced. Now having just finished act 2 I felt it was time to gather some thoughts about it.
Basically I want to praise the same things as everyone else, the voice-acting, its ****ing awesome. And the boss fights, really fun and kinda inventive. Some of the levels have been excellent to, Deadpool, Electro and Sandman's levels are the best so far. The worst one was Scorpion but the kinda fun boss fight at the end made up for it. All in all it haven't been one level that struck me as plain bad. Although the 2099 levels have been the least fun, but that has more to do with the futuristic design (while undeniably cool) not really doing anything for me.
The camera isn't the greatest but it's never been totally in the way, except for when wall-crawling. Still when crawling is mandatory (2d segment in Vulture level, short segment in Deadpool's level) it works well. The animations for it are good to.
Well there you have it, my three months late 2/3s through impressions. If anyone was interested that is.