The story is a little more convoluted than in the first movie, but fortunately director Favreau and screenwriter Justin Theroux (Tropic Thunder) don't make the same mistakes Sam Raimi made with Spider-Man 3. Sure, there is more than one villain, but the only "active" villain is Ivan Vanko; Justin Hummer is more of an instrument, and is not a classic villain in the sense that he is neither intimidating nor particularly dangerous. He only has the "resources."
Those who have seen the first installment might have noticed that, while the movie was excellently-written and acted, it kind-of-suffered during its climax because of some weak action. Well, this certainly isn't the problem here, since Iron Man 2 provides with some of the best action you'll see this year. Unlike, you know, a film like Transformers 2, the machine-on- machine battles in Iron Man 2 are actually exciting and tense because we know there are people behind those suits; because those people have been well-developed throughout two movies, and because Favreau, unlike Michael Bay, doesn't feel the need to shake the camera as much as possible and cutting every millisecond while shooting an action sequence.
Performances, much like in the previous film, are absolutely perfect. Robert Downey Jr. is Tony Stark, there is no doubt about it, and even in the film's weakest scenes - which are very few -, Downey makes the movie work. This time around, Stark is dying - the substance that makes the suit work and keeps him alive is actually killing him - and Downey Jr. now portrays Stark not only as a charismatic playboy, but also as a somewhat deeper character, who resorts to alcoholism because of all his problems. This alcoholism is not the main point of the film, though - it certainly is addressed, but it's something that gets dismissed rather quickly. This is for the better, I believe - even more problems and another sub-plot would have only hurt the film, and I'm sure the filmmakers will be able to explore this characteristic of Tony Stark in a deeper manner in subsequent films.
Don Cheadle, replacing Terrence Howard from the previous movie, is effective as Jim Rhodes. (He's even got some great one-liners.) Gwyneth Paltrow returns as Pepper Potts, and her relationship with Tony manages to move forward a little. There's great chemistry between the two of them, and they've got some great scenes together. Mickey Rourke is just great as Ivan Vanko - the majority of his dialogue is in Russian, and although he isn't precisely three- dimensional, we know just enough about the characters for him to remain both (a little) mysterious and intimidating. Sam Rockwell is also delightful as Justin Hammer - a very coward and unlikeable characters, that's for sure, but Rockwell manages not to turn him into a caricature. Scarlett Johansson, on the other hand, is just superb as agent Natasha Romanoff. With this part not only does she prove that she's the sexiest, most beautiful actress alive - one just has to hear men's reaction in the theatre whenever she appeared on- screen -, but also that she may be able to hand an entire action film by herself. She was just... *sigh*... amazing.
So is the film perfect? Not really, but its faults are small enough for them not to hurt he overall quality of the picture. Still, while the John Debney's score wasn't particularly awful or bothersome, it simply was... mediocre. There's nothing memorable or outstanding about his music. It's just... there. Completely forgettable. On the other hand, while I certainly was excited about the presence of a couple of AC/DC songs (Shoot to Thrill and Highway to Hell), I expected more of them, at least three or four, not just two! I mean, there's a reason why the film's soundtrack is made up entirely of AC/DC songs right? (I already bought it, by the way, and it's a nice re-collection of classic songs.) For example, if you know AC/DC has a song called War Machine and one of the characters in your movie is called "War Machine"... wouldn't it be logical for you to put that song in the film? Hopefully they're saving it for the next installment or something.
Anyway, those faults aren't particularly big, and the film as a whole is just amazing. It had been some time since I last left the theatre so excited. I mean, I am studying film-making, and when I left the theatre after watching Iron Man 2 I just thought "this is the kind of film I want to make." And by that I don't mean a superhero movie necessarily... I mean a film that does so many things correctly: it's laugh-out-loud hilarious at times, but it's also incredibly exciting. It's got some amazing special effects, interesting and believable characters, great performances, a complex but effective plot and it even works as a set up for a bigger universe of superheroes. Once again, Iron Man 2 is the best film I've seen this year so far, and I just can't imagine any blockbuster being more successful. I'm definitely seeing it again a couple of times in theatres... yes, it's that good.