War and Peace, Hampstead Theatre, London

Helen Edmundson's adaptation of the enormous Tolstoy novel is full of Russians dancing, striding, climbing, crouching, brawling, leaping, duelling, whirling. There is a lot of whirling. Men hug women above the knees, hoist them up, and pirouette so often that the innocent may think this the customary greeting in the early 19th century. But, while the energy levels hold up throughout Nancy Meckler and Polly Teale's production for Shared Experience, the intellectual and emotional ones remain shallow, and at times these aspects are treated so brusquely as to distort them.

When Prince Andrei questions his friend Pierre Bezukhov's improvements in the lives of the peasants, saying they ought to be worked till they drop and, when ill, left to die, he does so as a disillusioned and embittered man, envying the poor for the oblivion of exhaustion and death. Here his sentiments are so brief, so cold that some in the audience gasp at such villainy.

The vigorous motion that never rests long enough for us to become involved with any character results partly from the quixotic nature of the enterprise: though, at nearly six hours, this version is about 90 minutes longer than the one presented at the National Theatre in 1996, one would need almost twice the time to do justice to the narrative, to the characters and their spiritual quest. The plot often become a series of speaking telegrams, announcing that Pierre has inherited "one of the largest estates in Russia! Forty thousand serfs! Millions of roubles!" or that, at a party, "the eyes of all Moscow will be on you, Natasha Rostova".

Another problem is the undistinguished performances. The Andrei of David Sturzaker is pinched and parched, never evincing to any noticeable degree his growing love for Natasha or for humanity. Barnaby Kay's Pierre is, in contrast, a lumbering oaf, bereft of social graces but seething with passion. In fantasy, he pushes a pretty woman on to her back and rocks up and down between her legs, shouting, "I am in the abyss!" At the same time, he carries on talking to Napoleon – the emperor strolls on every now and then for a chat with Pierre, whose feeling for him changes from hero-worship to hatred.

Richard Attlee's Napoleon poses with his right hand inside his waistcoat and talks like a nagging wife of our time ("Feeling sorry for yourself again? You're pathetic."). Natasha, the love of Pierre's as well as Andrei's life, is, as played by Louise Ford, a classic case for Ritalin in her early scenes as a 12-year-old, leaping and rushing and romping without a break. When this strident childishness ends, Ford doesn't put charm or womanliness in its place – her character remains, though more stiffly, merely self-absorbed.

Far more sympathetic and appealing performances can be found in the lesser parts. Vinette Robinson is stylish, heartless, and unexpectedly touching as Pierre's unhappy wife; as the companion of Maria, Andrei's sister, she combines strength, sweetness, and an engaging vulnerability. Jeffery Kissoon, always a pleasure, is here especially welcome as Andrei and Maria's appallingly outspoken father, his hilarious insults bubbling up from a well of misery. The daughter, continually derided as useless and plain, could have been a mere whimpering masochist, but Katie Wimpenny's Maria is a minor heroine of stoicism and unrequited love.

Angela Simpson's set of shiny, scurfy grey marble, with gilt picture frames used to enclose actors singly or in small groups, is a fine combination of grandeur and decay. But the play as a whole lacks grandeur, especially in its too-short battle scenes. At Borodino, the attacking soldiers rush to the footlights, waving white sca ves. The brandishing of a sign of surrender during an advance seems symbolic of a show that, for all its activity, never takes us very far.

To 11 May (020-7722 9301; www.hampsteadtheatre.com)