PRODUCED BY Warp Films, hitherto purveyors of electronica to the cognoscenti, this inexpensive British thriller - an addition to the genre that showcases claustrophobic mayhem on too-small boats - offers a few useful pointers for film-makers seeking to deliver thrills on the cheap. It has a good build-up, features passable performances from about half the cast and makes good use of its nautical locations. Unfortunately, it may also make you want to vomit, writes Donald Clarke

The problem is not to do with the copious violence. Indeed, the best scene in the picture sees one of the characters vent bloody wrath with an outboard motor. You don't buy a ticket for a female revenge thriller without expecting a little blood in the bath.

The difficulty hangs around the film-makers' unresolved attitude to their antagonists' misogyny. Olly Blackburn, formerly a director of commercials, appears a little too keen to detail trangressive, violent sex in bizarrely comprehensive detail. If Olly fails to make a name for himself in features, he might wish to consider a career in mid-budget pornography.

Donkey Punch starts quite impressively with three girls from Leeds encountering a trio of beery geezers in Mallorca. The lads invite the girls onto the cabin cruiser where they work and, before very long, pills are being popped and vodka is being guzzled. A complicated ménage à quatre (or cinq perhaps?) ends in disaster when one of the boys indulges in a violent act rumoured to enhance the sexual experience. His partner dies and the group sets about disposing of the body. Tensions inevitably result and the girls find themselves waving knives and flare guns at the boys.

The first 45 minutes features a very steady, sinister accumulation of tension, but, when the shagging begins, the good ship Donkey Punch hits Squalor Reef and never quite regains its buoyancy. After the first few hours of sweating and groaning, it becomes all too clear that Blackburn and his team are happy to appeal to their audience's most voyeuristic instincts. The random slapping and punching that follows is carried out in such murky lighting that the distinction between the characters, never bold, blurs into puzzling oblivion. By the close, one almost longs for the relief that results from having an outboard motor rammed in the face.