Fanboys, lay down your noble swords. Watchmen the movie is here, and it is good.

As the opening titles of Watchmen kick in, an elegiac, graceful montage of photographs passes by, narrating and illustrating its slightly altered, kinky universe - Nixon re-elected for a third term, masked heroes forming a team called the Minutemen, before disbanding - backed by the downbeat strums of Dylan telling us 'The times they are a'changin''. Breath a sigh of relief, as this is the best of all possible worlds.

Zack Snyder, the dude who brought you muscles, testosterone and stylish man-nipples in 300, takes his meticulous hyper-real approach to cinematic art and marries it to Moore and Gibbons' seminal graphic novel.

In bringing Watchmen to the screen, Snyder and co. have accepted the boundaries of the medium and, for this theatrical cut, have sought to trim away the side-glances, extra-narrative material and metafictional depth that is one aspect of the comic's genius.

Gone is Tales of the Black Freighter, Under the Hood and other bits of colouring. Importantly, however, that still leaves more than enough story to give the film ample depth and complexity for its 2 hours and 40-odd minutes.

Set years after an act that outlaws masked vigilantes, the members of the Minutemen - a team of heroes - are spurred back into action by murderous mystery and international conspiracy. The narrative presents enough twists and turns to keep the audience engaged and gripped but, as any reader of the comic would know, Watchmen is more than action pulp. This manifests in the film as a conflicted, emotionally-charged, character-driven ensemble drama, as the distinct heroes - the nuclear demigod Dr. Manhattan (Billy Crudup), the Tom Waits meets Phillip Marlowe gumshoe Rorschach (Jackie Earle Haley), the affable tech-whiz Nite Owl (Patrick Wilson), amongst others - come together in debates on crime-fighting, politics and philosophy. Heavy on flashbacks, the narrative trajectory is as complex as the characters it creates.

Of course, as an adaptation, voices clamour for a list of changes made in transition. For the most part, the comic book is used as a very close source, provoking wonderful moments of frame-by-frame fidelity. Moments are exaggerated, extended or tweaked, either to give scenes more impact or to provide a more satisfying screen experience. Even though most of these changes are seamless and work within the logic of the movie, there are some howlers towards the end of the film, which drastically change the nature of the end-of-the-world plot and alters the final handful of scenes, and final glimpses of key characters, in the process. It is frustrating, because it jars with the lightness of touch seen in the rest of the film.

What makes Watchmen the movie stand out as a must-see experience, however, is found in its cinematic values. Having Snyder as director guarantees extreme violence and gratuitous use of slow-mo, although these action scenes are firmly rooted in emotional storytelling - for example, Nite Owl and Laurie Jupiter's (Marin Akerman) tentative forays back into crime-fighting, while bloody and brutal, are laced with triumph and catharsis thanks to the narrative's prior legwork.

Equally, the book contains myriad references to pop music, notably Bob Dylan's All Along The Watchtower, but use of original tracks to underpin key scenes and montages help set context and history, as well as providing a whole extra level of stimulation impossible in comics. Fans should have their breath taken away by the audio-visual impact of well-placed use of Nat King Cole's Unforgettable in the opening scene, or KC & The Sunshine Band's I'm Your Boogie Man as Nite Owl and The Comedian (Jeffrey Dean Morgan) quell riots in disco-era New York City.

Importantly, it is also used to great effect to characterise the mixture of tones and themes of the film's narrative strands - from the Mark Knopfler-esque guitar introspection for the awkward and tender relationship between Nite Owl and Laurie Jupiter to the towering strings of Phillip Glass' monumental modernism for Dr. Manhattan's wholly godlike creation story. Coupled with a flawless approach to set and production design, Watchmen looks and sounds great.

These production flourishes would be ineffective window dressing if not for the work of a well-chosen and competent cast. The lack of a discernible 'big star', and ensemble approach, allows each actor to stretch out and impress, inhabiting the complexities yet nailing the fundamentals of their roles. Billy Crudup, embraced by a blue glow and exposing a CGI penis for the world to see, speaks in an ethereal, otherworldly murmur, at the same time vastly assured and profoundly sad, but each member of the main cast deserve praise for their work.

Comparisons will inevitably occur between the film and the 2008 movie that 'made comic movies artful', The Dark Knight. However, it is in Watchmen's ensemble nature, wide canvas and deep complexity that it trounces the best efforts of Christopher Nolan's staggeringly successful blockbuster.

Far and beyond the dualities and binary-relationships of chaos/order, madness/determination and Joker/Batman, Watchmen presents a spectrum of morals and perspectives. It boldly interrogates the notions of heroes and villains, and the old adage of ends justifying means. It also performs the minor miracle of making all-out action sequences that are stylised, violent and yet not truly gratuitous. The comic came out at a time where violence and sex were still taboo, and due to the escalation of time, Snyder takes these up a notch. That is not to say he does it without grace, however.

Watchmen is still an adaptation, and is imperfect as a result. Taken out of its publication context, and with elements of its world and narrative shorn off, much of its charm and genius is missing. However, so much could have gone wrong; what we have been given is presented almost entirely faithfully, with enough tricks and style of its own to warrant a viewing. It is hard to imagine a better screen representation of this 'unfilmable' graphic novel.

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