Chekhov is thought to have written his sprawling "Play without a Title", known later in English as That Worthless Fellow Platonov, in 1880-81, when he was a 20-year-old medical student in Moscow. Although one of its later Russian titles was Fatherlessness, a theme that Chekhov had been tinkering with when he was even younger, it strikes me that a better label might be Bankruptcy. Most of the large cast of characters are hopelessly in debt - seldom has one seen so many IOUs flying around the stage - and almost all, young and old, seem both morally and emotionally "spent". The Doctor, as so often in Chekhov, is a key choric figure. But this one, Triletsky - engagingly played by Adrian Scarborough in Jonathan Kent's Almeida production - is a drunken buffoon who has long since lost interest in any medical procedure except "the extraction of wallets". Most of the peripheral characters, such as the foppish Kiril Glagolyev (Nicholas Boulton), who is addicted to expensive Parisian pleasures, or the two old men behaving badly with peasant girls (played with gusto by Bruce Purchase and Roger Swaine), are equally feckless.

As originally drafted, the play would run for at least six hours. In his new adaptation, David Hare has mercifully reduced this to three and a bit. Unfortunately, even neatly trimmed and sharpened, the piece continues to reflect both the immaturity of the author and his uncritical replication of the nastier features of the society he observed. This is exacerbated by the failure of either Chekhov or Hare to manipulate the audience's response with any clarity.

Misogyny and racism are pervasive. If anything, we seem to be invited to collude with Platonov's merciless taunting of the young student Maria Grekova for being so silly as to study for a degree in science: "adding to the sum of human knowledge by distilling the essence of bedbug". And at the close of the play, we are quite clearly meant to sympathise with Anna Petrovna's horror that her late husband's estate is not only sold off, but sold off to a Jew (a dignified performance by Bernard Kay, but the text offers no scope for Shylock-like scene-stealing) and managed by a vulgar grocer (played by Arthur Cox, again with few lines that transcend stereotype).

The narrative's Don Juanesque thrust is distressingly unreconstructed. The more Platonov yells at women, sometimes for being stupid, sometimes for being overeducated, the more they all adore him as "the only interesting man in the region", and each apparently believes that she is the one that he, in turn, adores. If we gained some sense either of psychological complexity or of Platonov's irresistible charm, this theme might still work today. But neither the text nor Aidan Gillen's performance helps much. The 20-year-old Chekhov appears to have found his 27-year-old anti-hero beyond his imaginative reach - he is far more Holden Caulfield than Hamlet - and Gillen seems too often to add more mess and muddle to Chekhov's already muddled conception. His voice, for instance, wobbles between various accents and registers - sometimes Irish, sometimes not - and his uneven rendering gives no sense of a Hamlet-like intelligence in control of his wildly contradictory "antic disposition". The most enjoyable scenes are often the simplest, verging on bedroom farce, such as those in the second act in which a drunken Platonov is pulled three ways between his pleasant, devout wife Sasha (Frances Grey), the swashbuckling widow Anna Petrovna (Helen McCrory) and his neurasthenic old flame, now newly married, Sofia Yegorovna (Jodhi May).

However, this ambitious and generous production makes spectacularly successful use of the very wide space of the former bus station at King's Cross that is the Almeida's current home. Paul Brown's set is superb. It gives a fine sense of the amplitude of the Voynitzev mansion in southern Russia, with its stream, its garden, its deep fields of sunflowers, its shadowy woodlands sheltering the gypsy horse-thief Osip (an excellent "physical" performance by Tam Dean Brown) and unknown horrors beyond. The palpable excitement of the audience when, in Act Two, Scene Two, the stream mutates into a gleaming railway track and the mansion into a humdrum schoolhouse is a reminder of the immediate thrill that only live theatre can give. Music by Jonathan Dove and sound effects by John A Leonard are also first-rate. For all these features, and for its strong, energetic cast, Kent's production can be strongly recommended. It's just a pity that young Chekhov did not write a better play, or that Hare's adaptation wasn't more radical.

Platonov is at the Almeida Theatre Company at King's Cross, London (020 7359 4404), until 10 November