Donkeys' Years, Comedy Theatre, London <!-- none onestar twostar threestar fourstar fivestar -->

Fun but not a complete farce

"Here we all are," a successful surgeon declares, musing bibulously on the passage of the years, in Michael Frayn's 1976 farce about a riotous Oxbridge college reunion. Half-cut, he delivers the line with the solemn wonder of someone who imagines that he has just unearthed a profound, universal truth.

Donkeys' Years - enjoyably revived in a condensed, partially rewritten version directed by Jeremy Sams - throws a group of middle-aged contemporaries into one another's company 25 years on. Ranging from a dodgy gay curate (a preeningly camp and precious Michael Fitzgerald) to the Secretary of State at the Department of Education (a platitudinous windbag whose parade of oily plausibility is hilariously conveyed by David Haig), the men become increasingly drunk and disorderly as they let loose their inner undergraduate.

In Noises Off, premiered six years after this piece, Frayn produced what is arguably the funniest play ever written - a mind-bogglingly ingenious farce about a farce. Donkeys' Years generates a great deal of goodwill, especially with such an engaging cast as the one assembled here, but it fails to soar to the delirious heights scaled by the later work.

This is partly because of the context. A gaudy at an Oxbridge college is, after all, an occasion of pretty licensed relaxation and misrule. Farce, though, thrives in conditions where everyone is forced to be on best behaviour and dementedly anxious that the façade of respectability will crack. It also needs to spiral off from a firm basis in reality.

Here the situation feels too contrived from the outset. So that the men can be left alone in the college at night with one woman, Frayn has to engineer a highly artificial set-up in which the staff (seemingly confined to Edward Petherbridge's head porter) down tools and leave on account of industrial action and in which, despite the fact that these bashes are a golden opportunity for touching old boys for money, the master and all the dons happen to be away - with the exception of Chris Moran's young, left-wing research fellow who becomes haplessly embroiled in the alcohol-fuelled high jinks.

The female left at the mercy of the alumni take-over is the master's wife, Lady Driver (Samantha Bond), who is well known to them all because, although she is now a ridiculously proper magistrate, in her youth she was a frequent overnight guest and dawn escapee.

Now she is searching for her lost first love, the absentee wild man Roddy Moore. Having secreted herself in his old rooms, expecting to find him there, she short-sightedly pours her heart out to the wrong, actual occupant, Snell (excellent Mark Addy), who is the play's most inspired stroke. This sublimely limited Welsh parasitologist ("The whole alimentary canal lay open to me! But then I became ever more bound up with worms, and the worms tied me to the small intestine") always boarded in digs and was left off lists so regularly that no one can remember him.

Now, under the heady influence of what he sees at the reunion, he becomes insanely determined to avenge himself for all the irresponsible undergraduate pranks he missed out on. Milady spends the night locked in this turned worm's sitting room.

Frayn has revised the piece so that some of the events that were merely described in the original (such as the drunken doctor, blinded in one eye after a fight, stabbing a syringe of sedative meant for Snell into several innocent backsides) are now fully part of the onstage shenanigans. Sams' pacey choreography can't camouflage, however, the fact that there isn't enough mad necessity in all the hiding and disguising and mistaken identities, despite splendid work from Haig as the politico, who, seized by back pain, has to waddle through the proceedings like an infant Max Wall. It's an entertaining evening that made me laugh out loud several times, but it's not first-division Frayn.

To 24 May (0870 0606637)