The biggest problem I had with the movie was the tone. I don't mind violence in movies, per se, but there was something about the violence here that struck me as being gratuitous and inappropriate. When one of the bad guys is crushed in his car in a junkyard in a much bloodier way than we need with some kind of classical-ish music playing in the background, we're very definitely getting into Clockwork Homage territory, and I don't think Kick Ass is the kind or type or place or whatever of movie for this. Would the movie have been less fun if the blood hadn't been smattering around like in 300? We're able to see when Kick Ass it getting his ass kicked outside the convenience store that this isn't a glamorpatch, we maybe didn't need the unmasking/torture scene to be served up with quite so much brutal relish.
Second biggest, why even bother saying this is taking place in New York when you're going to so little effort to make it look like it? There are plenty of things that are supposed to take place in New York that are filmed in Toronto, but it's not a good idea if you're doing it that way to have scenes where the Eaton Centre is looming in the background, its big Sears sign overhead, looking 100% totally and exactly like Yonge St. It's not a good idea to have a character walking past what is clearly a Toronto sidewalk recycling bin. There were some scenes where they cut from something where they actually were making it look like Times Square to where the next shot is very definitely Yonge St. in Toronto looking south. Holy Location Scout, Batman!
On a plot level, things work pretty much. The bad guy is a really cartoony kind of bad guy, but this is Kick Ass based on a comic book. Big Daddy/Hit-Girl seemed like they came from another comic book, but OK. The big problem for me here was with the Chris/Red Mist role played by Christopher Mintz-Plasse. For this movie to work, and for the underlying motivation as we move forward into possible sequels to work, we need to buy the blind-faced idolatry that Chris has for his cartoony bad-guy father. I didn't buy it. The movie does nothing to make me want to buy it. It relies 100% on the assumption that all children of mobsters should want to grow up to be in the mob just like growing up to be astronauts or firefighters. This motivation doesn't need to be like we're watching the young Henry Hill in Goodfellas, but nor should it rely entirely on what we bring to this movie from having watched Goodfellas. From the internal elements of this movie, it would have been just as believable for Red Mist to tell Kick Ass "jeez, my father turned out to be a total dick, don't miss him any, can we become a superteam?"
I didn't thrill to Clark Duke in Hot Tub Time Machine, I didn't thrill to him here as one of Kick Ass' high school buds. Evan Peters was much better.
Aaron Johnson's performance as Kick Ass/Dave Lizewski is another of those things in Kick Ass that seemed just a little bit off to me. Part of it is his fault. As an actor, he's no Christopher Reeve, at least not yet. The brilliance of Reeve's performance as Clark Kent/Superman is that we only see Superman bleed into the Clark Kent side in those exact instances when the actor wants and needs it to be. In Kick Ass, Aaron Johnson seems like he's trying constantly to announce to the world that he might be playing a dweeb, that he might be walking around this movie in a geeky haircut, but See My Smile, I Am A Movie Star. And part of the fault for that has to go to the director instead of the actor. That aspect of the performance could probably have been noticed in the dailies and toned down, the makeup and hair people could probably have made the dweeb a little less of a superficial skin on the character.
A lot of these problems seem to have the same root, that the people making the film just aren't 100% sure what they want to be doing with it.
All that being said, the movie is a nice way to spend a couple hours. Clark Duke aside, the cast is likable. If you like comics, how could you not want for your local comic book store to be like Atomic Comics? Maybe Midtown Comics in NY should install a booth or two overlooking Times Square. Getting your ass kicked aside, you do understand why Dave Lizewski might enjoy being Kick Ass, and the movie is not without its aspirational qualities.
If you think Kick Ass is the kind of movie you might like, then almost certainly it is a movie you will like. But it should have been better, could have been better, and I'm not 100% able to get rid of that aftertaste.