The Coen brothers could make slick, handsome genre pieces in their sleep, and that's what they've done with True Grit. Their version of the western, which takes its cue from Charles Portis's novel, is less jolly and knockabout than the well-known 1969 film that completed John Wayne's transformation into a leathery teddy bear and proved that Glen Campbell's attempts at acting could make grown men weep as readily as "Wichita Lineman" could. But a darkness of mood can still be placatory and there isn't a shot, cut or musical cue in True Grit to disturb the calm waters through which these most conservative of directors continue to drift.

The setting is Arkansas in the late 19th century, though it might equally be the inside of a snow globe. Snow is used here as magic dust to bring pop-up poetry to the plainest image and to vary the visual range of a sun-baked genre. The first thing we see is snow falling into a beam of orange light that streams from a house; it lends the illusion of movement to what would otherwise be a tableau. Sprawled on the ground is a man, shot dead by his employee. His principled, 14-year-old daughter, Mattie Ross (Hailee Steinfeld), spends the rest of the film urging others to bring his murderer to book.

Mattie has a lawyer's nimble mind, the rapid-fire words-per-minute of a screwball minx and twin plaits as thick as a hangman's rope. It's necessary that she comes across as smart but not smart-alecky - she has to ridicule her elders' failings, from their illiteracy to their hairstyles, without making us want to cheer when one slighted fellow takes her across his knee for a switching. Steinfeld, acting in her first film, achieves this by sounding credulous notes and transmitting faint flashes of panic from deep within Mattie's armour-plated confidence.

Her companion in the quest for vengeance is Rooster Cogburn (Jeff Bridges), the eyepatch- wearing marshal she has hired to catch her father's killer and whom she insists on accompanying against his wishes. We hear Cogburn before we first see him. The girl raps on an outhouse door, disturbing him at stool. The ungodly croak that responds could be his turd talking. The reality isn't much prettier. When Wayne played Cogburn, he was riffing indulgently on his own persona, whereas Bridges pulls the role over himself as though warding off winter under a pile of ratty blankets. His voice is almost unintelligible and he moves with a lurching uncertainty; there's a touch of Jabba the Hutt about him that is only exaggerated beside the prissy Texas ranger LaBoeuf (Matt Damon), who joins the manhunt. Even an actor of the calibre of Bridges has trouble finding anything new in the buddy-movie dynamic that kicks in whenever Cogburn and LaBoeuf bicker or try to outshoot one another.

What the Coen brothers believe they can bring to the western is anyone's guess. The quirky visual fillip remains their strong suit - the delightful strangeness of a hanged man dangling from a needlessly high branch, or an approaching horse that appears to be ridden by a bear. Yet they seem incapable of sustaining emotional effects for more than a scene at a time. Too often, they settle for either a simplistic melancholy, as in the recurring shots that gaze longingly backwards from Mattie's perspective, or an all-purpose wryness in the face of death - what might once have been called ironic detachment but has now hardened into a kind of gallows smugness.

True Grit begins with a corpse and ends with a lone figure beside a tombstone. Death is a constant presence on the journey, as it often is in the western. The human body is being taken apart here long before the worms are given a chance to tuck in: teeth are removed, fingers are severed, an arm is amputated, a tongue is bitten almost in two and a ribcage is filled with writhing snakes. But death is not quite the Great Leveller, as a Native American prisoner finds when he attempts to deliver his final words alongside other condemned men: a hood is pulled over his head before he can finish speaking. It is a piercing detail in its own right, but the picture has nothing more than a superfluous "Hear, hear!" to add to that mournful refrain from Clint Eastwood's Unforgiven: "We all got it coming."