It's the height of the Cold War and Richard Nixon has just won his third term of office. In an downtown apartment, a retired superhero known as the Comedian has been killed and nobody seems to care. Nobody except for a fellow hero named Rorschach. He suspects that the now discredited masked heroes of yesteryear are being killed off to prevent them from interfering something big. Exactly how big and from exactly what source he couldn't possibly have suspected.

Ask anyone who knows anything about graphic novels to list the 10 most influential and WATCHMEN is guaranteed to be on that list. Reduce that to the top 5 and WATCHMEN will still be there. Make it the top 3 and, whilst we won't guarantee it any more, it's still probably there. Written by Alan Moore and illustrated by Dave Gibbons, the comic book is a dark and layered tale of damaged psyches hiding behind capes and masks. It's the perfect antidote to the dayglo heroics of the likes of THE FANTASTIC FOUR, but it was deemed unfilmable. Who, after all would want to watch a superhero film about characters filled with fear and hate and haunted by their own demons? And then came BATMAN BEGINS and THE DARK KNIGHT and it became clear that dark and twisted superheroes is what the world really wants to see. After decades of development hell, WATCHMEN's time had come.

The film opens wonderfully with the bone crunching battle between The Comedian and an unknown assailant. It's a bone-crunching encounter that sets the tone for the rest of the action and Zack Snyder certainly knows how to stage action. These sequences crackle with life and energy without ever losing coherence or resorting to the handheld confusion of the post-Bourne action movie, but action is the least of what this film is about. What this film is about is the corruption of power. What sort of a person dresses up to dole out justice and who has the right to choose what justice is? Certainly The Comedian is a horrible, horrible human being and yet was he always that way or was he distorted by dealing with lowlifes and scum every day? Dr Manhattan, a man turned into an almost invulnerable God, finds the power distancing, his links with humanity ebbing away. It's meaty stuff, the kind that makes you think between bouts of bone crunching action.

It also looks fantastic. Taking the artistic ethic from the panels of the comic, it captures the visuality of Dave Gibbons illustrations. Some of the characters' outfits have been updated, but on the whole it really looks like a WATCHMEN film ought to look. The martian sequences are especially impressive.

There are some problems, though. The most obvious is the Dr Manhattan character. Rendered completely in CGI, he never even remotely looks real and some of the lip-synching is particularly poor, diluting the sterling voice work of Patrick Wilson who manages to convey the sense of a man who is no longer quite human, but not quite inhuman. The scene where he is making love to his girlfriend as twins and continuing with his work is unintentionally hilarious and most scenes where he appears, even in the background, he just manages to spoil the illusion of reality. The voiceovers from both Manhattan and Rorschach are also poorly judged and intrusive, as intrusive as the choice of music tracks proves to be at times. Jackie Earle Haley gets some particularly bad lines to say in these narrations that are supposed to serve as lights onto the inner workings of the characters, but there is enough strength in the story to not need it explaining with a clunky voiceover. It's also strong enough to not need some of the flashback sequences that illuminate the characters. Whilst the parentage of Laurie Jupiter might have some validity, do we really need to be shown the source of Rorschach's emotional issues or what happened to the Comedian in Vietnam? By determinedly, almost slavishly, sticking to the source material, the film does ramble on a bit through these backstories, becoming a bit flabby in the middle section. The makeup on Richard Nixon is also awful, looking nothing like the man.

Still, there is more to impress and admire than there is to complain about. The performances are mainly strong, with a stand out showing from Jeffrey Dean Morgan as the Comedian and a great performance from Malin Ackerman as Laurie/Silk Spectre II, whose warmth and humanity manages to anchor the more fanciful aspects of the subject. The story is certainly strong and the climax is stunning in its implications rather than its action, despite the unnecessary, slightly upbeat coda.

WATCHMEN is not the ultimate comic book movie and probably not the film that the graphic novel deserves, but it's still very good with occasional rough spots and moments of excellence.