His imagination fuelled by the films of Tarantino, Lynch and Scorsese, Martin McDonagh — a Londoner with family roots in Galway and Sligo — started the ’90s as just another twentysomething with dreams of making movies. Since he didn’t know how (and being on the dole didn’t help), he spent the rest of the decade writing plays. Even after McDonagh had set the theatre world on its ear with volatile dark comedies like The Beauty Queen of Leenane and The Lieutenant of Inishmore, he still claimed to prefer movies to plays. With the Oscar-winning 2005 short Six Shooter, he made a belated entry to his original medium of choice. Now that he’s made a full-length feature, two questions arise: is he better off here than he was in the theatre? And did the movies need him in the first place?

It’s not that In Bruges is a right can of shite, as one of McDonagh’s characters might’ve put it. The recent opening-night film at Sundance, it’s compelling for its rollicking energy, discomfiting laughs and deep undercurrent of despair. It’s just that McDonagh doesn’t venture too far from the territory of many of those movies that originally inspired him. Take away the picturesque setting and the two fine lead performances and In Bruges could be one of any number of post-Pulp Fiction crime pics about implausibly loquacious hardcases whose plans go pear-shaped.

In Bruges stars Colin Farrell and Brendan Gleeson (reuniting with McDonagh after Six Shooter) as a pair of hitmen who’ve been sent to the titular Belgian town in the wake of a botched job back in London. Ken (Gleeson) wants to make the best of it by seeing the sights. Full of nervous energy, Ray (Farrell) ain’t one for hanging around medieval churches. After some strange business involving obese American tourists, a racist dwarf and a sexy Belgian drug dealer, things get muckier for the pair and you know no good will come from the arrival of Harry (Ralph Fiennes), their hotheaded, foul-mouthed boss.

The bouts of grisly violence and sometimes iffy stabs at humour — the dwarf seems rightly pissed off to be stuck in this chaos — cause the film’s tone to veer wildly, with McDonagh failing to maintain the same steely control he has over the contents of his plays. In terms of style, the director is more timid — besides the effective use of handheld cameras in early scenes, In Bruges is otherwise conventionally shot with plenty of pretty views of Bruges.

If not for the sterling efforts of Gleeson and Farrell, it’d all be a lot dodgier. (As for Fiennes, his overly theatrical brand of villainy is better suited to Voldemort.) And when judged in comparison with McDonagh’s favourite flicks — as well as his movie’s closest kin, Stephen Frears’ unfairly forgotten 1984 comic thriller The Hit — In Bruges is hardly the triumphant foray into cinema that McDonagh’s playwriting prowess might’ve promised. Even so, it’s good enough to suggest he may crack it yet, provided he grows less in thrall to his heroes.