For the third entry in the Marvel Cinematic Universe, Marvel went back to the well with a sequel to its first entry, reuniting most of the creative team in front of and behind the camera. Unfortunately, this time it feels like a lot of wheel-spinning and set-up for future issues ... um, movies ... where most of the excitement is generated by promises of things to come rather than anything that is happening here. Scarlet Johansson's Black Widow is introduced and spends much of the film playing a functionary with nothing particularly interesting to do. Clark Gregg's Agent Coulson wanders in with the sole purpose of previewing MCU #4, "Thor." At least Samuel L. Jackson's Nick Fury has something going that affects this story and helps with the thematic resonance of fathers and sons. "Iron Man 2" might will have been subtitled "The Sins of the Fathers," with its A-story involving Mickey Rourke's bizarre performance as the son of a man who felt he was wronged by Howard Stark, who himself was no peach of a father to our hero Tony. But the movie is less interested in exploring this than in perfunctory world-building and in repeating beats from the first film, right down to a climactic battle that is a retread of "Iron Man"'s climax. The one saving grace of this film is Sam Rockwell as Tony Stark wannabe Justin Hammer. Rockwell, who was a leading contender for Tony Stark before Marvel settled on Robert Downey, Jr., shows what he could have done with the role. It's not that Rockwell would have been better than Downey's by now iconic personification, but it's fun to see a variation on Stark's snarky, egocentric megalomania that can hold his own with the master. And fun is something this film could have used a lot more of.