I have no gripes about the action in the movie, but a lot of the drama seemed to fall flat to me. I thought the film lacked the sincerity of the original and a lot of story-driven moments felt forced.
My main gripes:
- Trying to use Hawkeye and his "secret" family as the emotional backbone of the movie
- The twins came off as pretty lame to me, overall. Elizabeth Olsen is super hot and a great actress, but I felt that she didn't get to show her chops. Also, her accent sucked.
- A little too much setting up for future films, that made much AOU feel like a placeholder and commercial for the next round of films to come
- Some questionable editing that made it obvious some things were cut out or trimmed down
- Ultron came off as a little too much of a cheeseball to me. I get what they were trying to do and that he was meant to be like the "evil" progeny of Stark, but I wasn't thrilled with the characterization.