Rabbit, Lyric Hammersmith, London

The Australian dramatist Brendan Cowell's play Rabbit is a wild variation on the Guess Who's Coming to Dinner formula. Here, though, it's not racial difference that will freak out the parents, but the fact that their prospective son-in-law is a hip-hop artist and a junkie. Dad is a reactionary radio talk-back jock on a prejudice-reinforcing programme called The Real World. Mum is a fading beauty who keeps her wrists supple by fixing vodka martinis.

When they arrive at their mountain-top holiday home, bearing supper in the shape of a still-living rabbit in a cardboard container, the couple are confronted with the stark news that their daughter Madeleine has had enough of being Daddy's studious little achiever and intends to drop out of university and become a butt-naked rap artist in seedy clubs. Her father has not only a bunny in a box to kill but a major cat to let out of the bag - a moggy that's on its ninth life.

The piece, which was premiered in Sydney last year, is performed here by Frantic Assembly, a physical-theatre company that has built up a large and dedicated following with its imaginative finger-on-the-pulse explorations of what it is like to be young now. It has worked with writers before (as when it collaborated with Abi Morgan on Tiny Dynamite). But Rabbit (directed by Scott Graham and Steven Hoggett) is the first time it has brought its distinctive methods to bear on a pre-existing text.

The result can sometimes look weird and disjointed. Sam Crane is very funny indeed and oddly touching as the hip-hop junkie, the kind of youth who you sense would be cowering in a corner if he weren't strutting around in a floppy, drug-fuelled pretence of being the coolest rapper on the block. (Given the mountain-top setting, he and his partner could call themselves Niggaz with Altitude.) For his character and that of the daughter (Helen Heaslip), the stylised exaggeration of subtext through disciplined physical abandonment works well. But when the others embark on, say, synchronised signallings of awkwardness, you feel that the choreography to recorded music has been tacked on, rather than organically evolved, and that Rabbit, a very wordy play with a sharp ear for dude-speak and menopausal moaning, is already heightened sufficiently by its linguistic ebullience.

The piece has some shrewd things to say about the penalties of "plastic parenting" (contact primarily through credit card) and about the dismayed resentment of the middle-aged at the "because we can" generation. "Let's download Asian teenagers going to the toilet on each other - because we can," scoffs the father (played with an amusingly grim grumpiness by David Sibley). There were several times when this vividly voiced culture clash had me laughing out loud. Less successful are the show's reflections on what facing up to mortality can do to a family. I don't want to give too much away, but in the darker, more surreal second half, the story lunges into the woods outside, where there is nude bonding, a chauffeur who isn't allowed to go to the deathbed of his baby son, and a reworded rendition of "They Can't Take That Away from Me". By coincidence, the piece opens during a run at the Barbican of Robert Lepage's The Far Side of the Moon, which finds a wonderful metaphor for the loss of parents in an astronaut floating alone in emotional space. By comparison with the poetry and sustained development of that image, Rabbit's musings seem not so much youthful as juvenile.

Ends tomorrow (020-8741 0824); then Arena Theatre, Wolverhampton (01902 321321) 28 & 29 Oct and touring