I saw the movie and it is not that bad. It definitely doesn't deserve 29% on RT, thats crazy! I think releasing late summer worked against it because critics are no longer in the mood for this kind of movie.
Kick Ass 2 is actually my second most enjoyable movie I've seen so far this summer, number one would be star trek 2. However this movie suffers from a similar problem as star trek, the first one was so good that the second just can't live up to it. Kick Ass 2 was just good, and that is enough to disappoint when the original was great. Its hard to really put my finger on whats wrong with it, the movie feels tonally confusing in parts, whereas the first kick ass just seemed to work. Still a decent movie for the action scenes alone.