Jump, Peacock Theatre, London <!-- none onestar threestar fourstar fivestar -->

If only they'd stick to the wonders. I am susceptible to martial arts: I like Bruce Lee; I like Jackie Chan. I am even prepared to accept those tin-foil swords that flap when brandished. But most martial-arts productions are shoddy frames for the stunts. Many go in for Eastern Wisdom -Jump takes to stale slapstick.

The show was created by Ye-Gam Inc in 2002, and has appeared at festivals from Edinburgh to Dubai. The performers, all trained gymnasts or martial artists, were taught by the Korean women's gymnastics team coach. Jump's gimmick is the comedy, casting the artists as a typical family.

In practice, that means a bunch of stereotypes. The uncle is the drunk, down to his red-painted nose. The mother chases after the father, who eludes her much as Kenneth Williams eluded Hattie Jacques in Carry On films. Burglars break in and get caught up in the family's rows.

Though this is limited, it could be lively if it had more spontaneity. But there's no characterisation to these characters. There are two old men: the grandfather and an extra, unexplained ancient. The performers are young and agile, so they lay on the doddering to let us know they are old, before turning a backflip or two. The backflips are good, but it's a long wait. Too much of Jump keeps us waiting, sitting through Dong-Jun Lee's wailing rock music.

There are brighter ideas. The first of the family fights builds up to a movie-style battle scene, complete with slow motion. The pacing could be tauter, but the low-tech variation on film techniques is funny.

Comic points are made heavily. Only two of these performers show much dramatic sense. Chul-Moo Kim, the second burglar, is an actor first and a martial artist second. He does a few somersaults and high kicks, but he's there as a comedian: the chubby bungler. He bounces through it all with frank good humour, relaxing easily into the jokes.

In one scene, members of the family risk their lives to protect the others, stepping up to the burglar's gun as sad music plays. Young-Sub Jin, playing the father, is by far the best. He's funny because he takes it seriously, pulling himself into a determinedly noble attitude.

The last 10 minutes are the best thing in Jump. The cast come back for a straightforward display of impossible feats: swinging poles, running up walls, turning somersaults. It's a cheerful finale, without a comic walk in sight.

To 26 February (0870 737 0337)