This may be considered one of the few missteps that Marvel has produced, and even with that being said it's still not a terrible film. What works is Mickey Rourke as Ivan Vanko, who seeks revenge against Robert Downey, Jr.'s Tony Stark for the death of his father. Definitely some harrowing scenes between them. Comic-relief from Sam Rockwell as arms dealer Justin Hammer, and strong support from Samuel L. Jackson as Nick Fury and Scarlett Johansson as Black Widow in her first appearance in these films. What doesn't work are some major subplots that are resolved way too easily. Don Cheadle replaces Terence Howard as Rhodey, who becomes War Machine.
Of the film, Downey details, "My take was that once you tell an origins story pretty well, that’s usually where things start to get dull, and one or two or three things start to happen over and over again. So, we made Tony Stark’s challenges very much outside the usual realm of activity. As much as anything else, it’s much more of a side job for him the second time around. And the great thing, too, is that the Marvel universe is wild; it’s so far out. That’s the big balance to strike. It would be so easy to go so far out it would be intergalactic and nothing would be grounded in reality anymore. I think what worked for Iron Man is that it almost seemed like something from the cover of Popular Mechanics. These kinds of suits were starting to be made in the States and Japan, so people were responding to Iron Man almost as though it was a more of a high-tech James Bond. So how could we start to introduce elements of the storylines in the comics without becoming too outlandish, where it wasn’t rooted in some kind of reality? That’s my big thing, and the only thing that’s really been of any benefit with my—quote, unquote—successes recently, is that they have allowed people to trust my instincts more comfortably, and to give me a little more creative leverage. And that’s all that matters, because all the other stuff comes and goes."