It's a rule that holds for every office party, even if the gathering in question is a theatre-based send-up of enforced Yuletide carousing with colleagues: you must approach it in the right spirit. If you don tinsel and/or fluffy reindeer antlers, have an alcoholic sharpener or three beforehand and stick with friends for the duration, it's great fun. If you don't, purgatory and all places darker beckon.

The Pit is rightly garnering quite a reputation for its alternative Christmas offerings. After the success of Duckie's The Class Club last year, Christopher Green and Ursula Martinez, two alumni of this performance collective, take us to, and through, the December bash of an unspecified large corporation.

On arrival, we are divided into groups: "Creatives", "Executives", "Accounts" and the like. I was relegated to "Domestic Support", which meant gathering in a dingy green room, eating jellied fruits and listening to emotional team leader Mary (Vicky Ogden) talk about the difficult year - changes to shift work, restrictions on bleach use - that our team had suffered. Then it was off to the balloon-bedecked party venue where, as ever, everyone initially shunned the dance floor in favour of the bar.

Soon, a group of us were conga-ing gaily away but guests who forget their dancing shoes will feel the evening's longueurs more than most. For Cal McCrystal's production, although capturing nicely the slightly desperate milling-about integral to all such events, could do with a touch more pointing, to provide greater structure to the pattern of inter-departmental team games and naff "entertainment" acts that Green, Martinez and others provide. If you've never seen Lady in Red done as a striptease, or one performer impersonate both Olivia Newton-John and Barry White in the same number, here's your chance.

The next morning, I awoke with a fuzzy head, sore feet and pleasant memories but did feel that a lot of what cheer I'd experienced I'd generated myself, along with friends Beatrice and Robert. Theoretically, this is a superb idea, so perhaps the "Creatives" could hone it for next year? As for me, I'm off to clean up.

• Until 29 December. Information: 020 7638 8891, www.barbican.org.uk