A few too many subplots and villains can’t keep this sequel from being relatively enjoyable. Robert Downey Jr. still dazzles as Tony Stark, the billionaire who outed himself as a superhero in the first film. This time, he battles an evil Russian scientist (a hammy Mickey Rourke), a crooked arms developer (a splendid Sam Rockwell) and a slimy senator (Garry Shandling, a victim of horrible plastic surgery). On top of all this, Stark must deal with his friend Rhodey (Don Cheadle, replacing Terrence Howard) stealing one of his suits, and the fact that he is dying. You also get Scarlett Johansson as a butt-kicking spy, and all sorts of teasers for the upcoming Avengers movie. It seems like director Jon Favreau and screenwriter Justin Theroux were trying to make four movies in one. It’s a mess, but it’s an enjoyable mess.