All that aside, Twin Town is funny, closer to the insular oddness of an Ealing comedy than the almost compulsive exhibitionism of Boyle's Trainspotting. Moody and sly, Twin Town is really about family and loyalty -- and the ways such soulful altruism can really ruin somebody's life.

Even on a bright day in Swansea, the Welsh town where Twin Town takes place, the sky seems grimy, as though someone needs to get on a ladder and scrape a layer of barnacles off the sun. Instead, Fatty Lewis (Huw Ceredig) and his barely capable co-workers head off with ladders to do some roofing work. When Fatty takes a tumble off a roof and the priggish Bryn Cartwright (William Thomas) -- the roofing contractor who essentially runs the town -- refuses to pay for Fatty's medical care, Twin Town gets going.

The picture doesn't bother to make anybody look good -- the cops are either corrupt and lax or dimwitted and ambitious about their corruption. The two families at the center of the picture, the Lewises and the Cartwrights, aren't competing for audience sympathy either. The Lewises scream and battle like Welsh trailer trash; Fatty's sons, twin brothers Julian (Llyr Evans) and Jeremy (Rhys Ifans), aren't even really twins, though these boys are definitely backwash from the same gene pool. Too chowderheaded to be psychopaths -- like lizards, they seem to be breathing through their eyelids -- they lumber from one thrill to the next, spilling beer and dope ashes on their rotting clothes as they stumble along.

The one thing they can get into their heads to do is get back at Bryn by sabotaging the karaoke contest in which he has entered his daughter, the bonny Bonny (Jenny Evans); this small-time feud then erupts into something as ugly as the phrase Dylan Thomas saddled Swansea with when he called it "a graveyard of ambition." Director Kevin Allen settles into an easy, low-blood-pressure rhythm, so the jokes he and co-writer Paul Durden wring out of the settings often seem to belch out of nowhere. Allen and Durden have equal contempt for everybody, be they working class or deluded bourgeoisie; even those who don't deserve to be spat upon end up with big wet gobs on their faces. And the depiction of Swansea's small-minded population and its infatuation with a limited life is extraordinary; the attention paid to the karaoke alone is hilariously unsettling.

It's up to the actors to infuse a hint of humanity into Twin Town, and the cast ably navigates the complicated tone. But in the end, Allen and Durden try to show an interest in fair play, and, surprisingly, Twin Town winds up as a kind of morality tale, with the karmic scales being righted. It's a slender tale but deftly told; and, more important, the world is surely enough created that Twin Town survives the introductory skit tacked on for American audiences that explains the difficulties they might have in deciphering the dialect barrier. Twin Town may not be Trainspotting, but mercifully, it ain't pitched like the cringingly cute opening either.

Twin Town.
Directed by Kevin Allen.With Llyr Evans, Rhys Ifans, Dorien Thomas, Dougray Scott, Huw Ceredig and William Thomas.

Not rated.
99 minutes.