THEATRE / Round-Up: West End ho]: Sarah Hemming reviews Neville's Island, Beautiful Thing, Once on this Island and Only the Lonely

At one point in Neville's Island (Shaftesbury Apollo), Tim Firth's wonderfully funny comedy about four middle managers marooned in Derwent Water, Angus from distribution bemoans the congenital greyness of the middle class: 'We just emerge from the fog and everyone moves over a bit.' It's a nice line but it also sums up the dark underside to Firth's comedy, for though it's often hilarious, this tale of four middle-aged, middle-class, middle managers, facing the truth about their mediocre lives, is also pretty bleak.

In that respect Firth is not unlike Ayckbourn, the master of bitter truths delivered with a smile. He shares with Ayckbourn, too, the shrewd eye for English malaises, and the ability to satirise his subjects while still pitying them. But Firth, at 29, already has his own voice, matching his sharp verbal humour with physical comedy, and a playful approach to staging. He makes his West End debut (after showings in Scarborough and Nottingham) in confident style.

Neville, Angus, Roy and Gordon are businessmen on an outward-bound exercise. But they wreck their boat on a desert island, and with it all hopes of outdoor bonding. The absurd premise sets the tone for the evening, which keeps up the horseplay all the time while the grim truth about these men's empty lives is stealing up on them.

Jeremy Sams's deft production brings out the changing moods of the play and has a fine cast. Michael Siberry is touching as Roy, whose beatific smile can't disguise his fragile sanity, Jonathan Coy frays before your eyes as the well-meaning team leader, and Paul Raffield is particularly strong as Angus, the plodding pedant. Tony Slattery's Gordon is the cherry on the cake: a bombastic bully who rattles around the island like a machine gun on the loose.

Another distinctive voice in the West End is the 26- year-old Jonathan Harvey, whose play Beautiful Thing is now at the Duke of York's. This touching story of a schoolboy on a Thamesmead estate who falls in love with the boy next door started at the tiny Bush Theatre, but it travels well. It's an affectionate, tender comedy, full of lovely observations, that needs, and gets, a sensitive production by Hettie Macdonald and detailed performances from the cast. Amelda Brown, in particular, is hugely enjoyable as the tough mum with a soft centre, and both play and production catch the evanescent mood of a summer in adolescence.

Into the West End from Birmingham Rep comes Once on this Island, making a tremendous effort to give you a good time. The usually somewhat municipal Royalty Theatre is transformed into a 'Caribbean Island' with palm trees sprouting from every corner. The effect is rather bewildering - but the show itself is charmingly done. The tale of Ti Moune, a girl who defies the gods by falling in love above her class, it is given a polished production by Gwenda Hughes and David Toguri, and Lorna Brown has a fresh innocence as Ti Moune. What holds it back is the music. When Sharon D Clarke fills the stage with her song as the goddess of fertility it really takes off, but too often Stephen Flaherty's music is rather bland: rum with too much coke.

It's short and sweet, however, which cannot be said of Only the Lonely, Bill Kenwright's tribute to Roy Orbison, which arrives at the Piccadilly from Liverpool Playhouse. Larry Branson is credible as Orbison - he looks and sounds like him - and the music is good. But the script is woefully trite and, after 42 numbers, you emerge punch drunk.