Watership Down, Lyric Hammersmith, London <!-- none onestar twostar threestar fourstar fivestar -->

These bunnies are hopping

In this new version of Watership Down, the foxes and stoats wield flick knives and the rabbits defend themselves with kung fu. Welcome to the weird and wonderful world of Melly Still, the director of Coram Boy who reduced the younger members of her audience to tearful, quivering wrecks with her vision of lost children in 18th-century London.

As if this were not enough to put off overly protective parents, this time round she has teamed up with Rona Munro, the unrelentingly dour and gritty playwright who recently brought Elizabeth Gaskell's grimy tale of grinding poverty, Mary Barton, to the Royal Exchange in Manchester.

This is, surprisingly, the first professional stage outing for Richard Adams's much-loved children's classic. His original tale about a group of rabbits who leave their home to found a new, utopian warren elsewhere was partly based on his own experiences as a captain during the Second World War. Still has taken this idea and run with it, to the extent that her rabbits are defiantly, confusingly even, unbunny-like. No tails and floppy ears here; instead, the cast is dressed in country casual style - woolly diamond-pattern socks, cable-knit jumpers and, in a tiny concession to the bob-tail, bobble hats. The does look like wholesome, hearty Land Army gals, while General Woundwort (a charismatically evil Barry Aird) goes the whole hog in a military coat, jack-boots and peaked cap.

A choreographer before she turned her hand to directing, Still has produced a highly physical spectacle. Much use is made of two trampolines for hopping around, while diving into the burrow is done simply by leaping through a hula-hoop. There's also a particularly joyous scene with space-hopper lettuces and pogo-stick carrots. The rest of the time, though, it's difficult to succumb to these rabbits. A couple of them will give the odd twitch of a nostril or a wide-eyed stare, but otherwise they limit their animalism to rather breathless interludes of bouncing around.

Confusingly, this isn't the case for the other animals in the cast, who are much more interesting to watch. A cat swings her rope tail sultrily behind her as she prowls about the farmyard; a stoat holds two daggers in front of his face as pointy teeth. Best of all is Richard Simmons's Kehaar, the seagull who helps the rabbits during their perilous adventure. With a French accent straight out of 'Allo 'Allo and curious white Shaolin robes, he cuts a comical figure but also produces a real sense of flight with his whirling dervish moves. The closing scene of the first act, as he flies up above the billowing green fields, "baa-beasts" and toy train set, giving the rabbits the wisdom of his bird's eye view, is especially charming.

Still's production does not shy away from the violence of Adams's book, where death lurks around every corner - a mother is forced to eat her own babies as there is not enough room in the warren and a fox kills a rabbit with one bite (slitting her neck with a knife). In their defence, the rabbits put their hind legs to good use with tae kwon-do and kung fu. The kickboxing scenes are enhanced by sound effects provided live on stage by the musician James Keane, and the cast help out from the wings, howling into microphones and beating on the walls of the set to evoke the noise of the wild.

But, all in all, it is almost too much of an assault on the senses. The boundless energy of the cast cannot be faulted, but their exciting fight scenes, precise choreography and inventive sound effects are never allowed room to breathe. There are some nice moments ("you're pulling my ears!"), but we are not given time to enjoy them and the emotional resonance of the script suffers as a result.

Still is determined not to patronise her younger patrons with fluffy bunny costumes and a saccharine tale of life in the wild, but her frenetic staging seems to assume that kids require constant action. It's one thing to encourage their imagination; it's another to leave them feeling confused.

To 13 January (08700 500 511)