Sequels seem to work better for superhero films than for any other genre. Perhaps it's because comics themselves are nothing but sequels, each story an episode continued from the last, ever continuing and evolving. Iron Man 2 may fall short of the surprise hit Iron Man, but not enough to dampen fans’ enthusiasm for the franchise.

First, the good: It was a bit of brilliant casting for the first film to cast Robert Downey Jr. as Tony Stark, the narcissistic billionaire whose genius at weapons manufacturing allows him to build the Iron Man suit. We meet up with him again, this time dealing with the repercussions of revealing his secret identity in the last film, and watch as he slowly loses control of every aspect of his life. His glowing blue chest battery that powers the Iron Man suit – and his heart – is slowly killing him, introducing fatal toxins into his blood stream. He has no alternative though: if he removes the battery, he will die – and quickly. To add to his troubles, his company is in trouble. Industrialist Justin Hammer (a frolicking Sam Rockwell) has eyes on his Iron Man technology, and employs Russian criminal and techno wizard Ivan Vanko (Mickey Rourke) to steal it. Between the pressure of attacks on his health and his company, Stark takes to drinking – a dangerous pastime for the operator of a fully-armed Iron Man suit.

The film also introduces some new allies – Scarlett Johansson as Natalie Rushman, Don Cheadle as Rhodey (a.k.a. War Machine) – and fleshes out some others. Jon Favreau, in a small part as well as directing the film, plays Happy Hogan, Stark’s chaffeur, and Samuel L. Jackson as Nick Fury of S.H.I.E.L.D. Jackson, as usual, owns every line of dialogue, infusing every glance and gesture with macho cool.

Now, the bad, which isn’t so much bad as mediocre: The film takes much too long following Tony Stark around town in the opening. It’s nearly a third of the way through th e film before he even meets the villain. And as for Ivan Vanko, he ’s not much of a v illain. We see him in the opening credits, splicing together bits of machinery while laughing with his cockatoo, but then he disappears from the film, not returning except to slash up Stark’s race car with his electric whips. This scene adds nothing to his character, and, action centerpiece that it is, seems rather unnecessary. Vanko goes to jail, only to be broken out in a lackluster scene, and then begins working for Justin Hammer. Why not have Hammer recruit Vanko to begin with? Forty minutes cut. Mickey Rourke is a competent actor, and he adds details to Vanko that a lesser actor wouldn’t even consider (he even researched Russian tattoos and visited a Russian prison, speaking half his dialogue in Russian, the rest with a heavy Slavic accent), but his character isn’t sinister enough. His motivations – that Stark’s father fired his father – seem weak, and he doesn’t have what all great comic book villains need: a hint of madness.

Gwyneth Paltrow also gets more screen time in Iron Man 2 than previously, but her scenes show her as a weak character, not able to handle running an empire and more adept at being a mild-mannered secretary. Especially when compared to the ballsy Scarlett Johansson, Paltrow’s Pepper just seems like she should have stayed home. Her scenes feel like the equivalent of showing twenty minutes of Alfred trying to run Wayne Enterprises in Bruce’s absence – it doesn’t need to be there.