PUBLISHED : Thursday, 12 March, 2009, 12:00am
UPDATED : Thursday, 12 March, 2009, 12:00am

Starring: Billy Crudup, Patrick Wilson, Malin Akerman, Matthew Goode, Jackie Earle Haley, Jeffrey Dean Morgan
Director: Zack Snyder
Category: III (Imax version); IIB (35mm version)

For the uninitiated, skimming through the credits of Zack Snyder's adaptation of Alan Moore's graphic novel would probably prompt the question: Who cast Watchmen, and why? All the actors are unlikely superheroes: Billy Crudup's best-known role remains playing a disgruntled rocker in Almost Famous; Patrick Wilson is the star of suburban drama Little Children, from which Jackie Earle Haley earned an Academy Award nomination for playing a paroled paedophile; Matthew Goode has carved a niche playing British toffs; and Malin Akerman's big break came in romantic comedies such as The Heartbreak Kid and 27 Dresses.

Snyder's choices speak volumes about Watchmen. It's not simply a testosterone-dripping, CGI-drenched action fantasy; the strength of the sprawling, 165-minute spectacle is its innovative approach to demonstrating how superheroes can be incredibly flawed, mentally damaged individuals.

In a film that should have preceded movies such as Hancock and Christopher Nolan's Batman Begins (this film was stuck in development hell for nearly two decades before production began in 2007) Watchmen unleashes masked vigilantes with attributes that are far from heroic. Among them is a rapist (Jeffrey Dean Morgan's the Comedian, above with Carla Gugino as the first Silk Spectre), a bitter right-wing moralist (Haley's Rorschach, who also provides a grinding voice-over throughout the film), a man who has retired from saving the world to become an unfettered capitalist (Goode's Adrian Veidt, aka Ozymandias) and a bumbling, overweight everyman, Night Owl (real name Dan Dreiberg, played by Patrick Wilson).

Watchmen is set in an alternate version of the US in 1985, with Richard Nixon having won the Vietnam war and still in power after a successful attempt to remove presidential term limits. The film begins with a hard-hitting sequence in which a masked assassin slays the now aged and jaded Comedian. His death alerts his former associates of a possible conspiracy to eliminate all Watchmen. The killing is swiftly put into context by a clever opening title sequence featuring an outline of a rewritten version of American history that marks the rise and fall of superheroes, with some intervening in key episodes during the post-war era (including a bizarre take on the Kennedy assassination).

The film's best moments happen in its first two hours. Snyder goes backwards and forwards in time to spell out the personal tribulations of each of the protagonists; the back story of the first Silk Spectre and the way her daughter, Laurie (Akerman), takes up her mantle; the way a freak accident transforms the nondescript scientist Jon Osterman (Crudup) into a godlike ubermensch, who is soon dubbed Doctor Manhattan by the US government for his role as the weapon to deter the Soviet Union from starting a third world war. Also shown is the Comedian's role, alongside Manhattan, in bringing Nixon the victory he needs in Vietnam, and the way the brutality committed during the war scars both superheroes.

Up until then, Watchmen is one big watchable epic, a crazed magnum opus that draws its energy from real-life politics (Nixon is represented along with Henry Kissinger and Pat Buchanan), film history (a Dr Strangelove-like war room makes an appearance here) and popular culture (the eclectic soundtrack features rock songs, a Philip Glass piece and Leonard Cohen's Hallelujah). The film unravels in the final stretch, however, as Snyder seeks to shape his brainchild back into the sci-fi blockbuster mould. The showdown between heroes and villain takes place in a denouement reeking of political naivety and deflating the anarchic (and sometimes bloody) glory of what has gone before.

Watchmen opens today