Screen Rant reviews Iron Man 2
Let's get the big question out of the way: Was Iron Man 2 better than the first film? Not quite.
Having said that, remember that the first film set the bar WAY high, so not topping it doesn't mean this sequel was bad. Far from it. What it means is that while I liked it a lot, I didn't quite LOVE it like I did the first film.
Iron Man 2 opens with a voiceover that takes us through the speech at the end of the last film where Tony Stark reveals that he is Iron Man. About six months have passed since that announcement, and since then Tony has been busy zipping all over the world intervening in international conflicts. Of course the U.S. government is not too happy about having a private citizen loaded with weaponry intervening overseas on behalf of the country, and they want the Iron Man tech turned over to the military.
The government is represented by Senator Stern (played with perfect pompousness by Garry Shandling), who can't convince Stark to turn over his private technology. This puts Tony on the opposite side of the equation with his good friend James Rhodes (Don Cheadle) who believes that sharing the technology with the military would lower the risks of having to depend on just one man. Speaking of Rhodey, it was great how they buried the whole "Terrence Howard isn't Rhodey" thing with this line from Cheadle right at the start of the film: "It's me, I'm here, deal with it and let's move on." There's also a nod to fans of the first film in Tony's first appearance where he says "It's good to be back" and asks the audience if we missed him.
Stark Industries' rival is Justin Hammer (Sam Rockwell), another wealthy weapons manufacturer who is the less charismatic version of Tony Stark. Hammer is jealous not only of Stark's Iron Man tech, but of the man himself (Hammer comes off like a used car salesman who wants to be classy but doesn't know how to do it). He's developing his own armor technology but it's years behind Tony Stark's.
One of the main plot points driving Iron Man 2 is the fact that Stark is being slowly poisoned by the palladium that powers the miniature arc reactor in his chest. It's getting rapidly worse and despite applying all his genius towards finding a replacement, he hasn't been able to find anything that works - he's dying and it's going to happen sooner than later.
While all this is going on we have Ivan Vanko (Mickey Rourke) over in Russia, whose dying father was apparently shafted big time by Tony's father, Howard. Vanko manages to build his own miniature arc reactor and vows revenge against Stark. Finally we have Scarlett Johansson playing "Natalie Rushman," an accountant who comes into the Pepper Potts/Tony Stark relationship.