Tim Minchin, Duchess Theatre, London

Tim Minchin won the Perrier Newcomer Award in 2005, helped by a concerted lobbying campaign. A year later, for this London run, the 30-year-old Australian musical comedian has enjoyed a similar ballyhoo, being promoted as if he were a hot rock-act.

While winning a comedy award in Edinburgh is not always a career-changing moment, Minchin has shown it can be a springboard. At £20 a ticket, he has prematurely joined the A-list of comedy stars.

You certainly get a professional, polished act. He's an accomplished pianist, lyrically dextrous and has both comedic and musical timing. Certainly the audience laps him up - at intervals - but his act only laps at me, then to wash over me. This is chiefly because - profanity and taboos notwithstanding - I find his songs too clipped and clean (like Ivor Novello without enough charm) and his in-between patter inconsequential.

Looking like a younger member of the same musical hobbit family that you imagine spawned Bill Bailey, Minchin tries to thrill with trills and rock-opera routines like "Rock'n'Roll Nerd", the supposedly semiautobiographical song about how it's hard to be cool when you are upper-middle class ("He hasn't spent a single night in prison/ He has no issues with nutrition") or a musical doodle like the in-joke "F-sharp".

More impact is made with "Some People Have It Worse Than Me", where he looks on the bright side of life, comparing his lot with "a policeman in Baghdad" or "a bus driver on the Gaza Strip". Elsewhere, context and melodrama seem to get the better of him. Other issue-led compositions such as "Canvas Bag" (on the environment) and "We Don't Eat Pork" (a peace anthem for Israel and Palestine) are essentially one-joke creations, yet they're fun and, though repetitive, they don't outstay their welcome.

However, the stand-up element isn't strong. The conceit that Minchin would probably be useless with women if he wasn't with his wife is cute, but nothing more. Elsewhere, he over-eggs a common joke about minicabs and elongates an initially more promising routine about evolution.

Minchin synthesises his two previous Edinburgh shows into a pacy full-length show of 75 minutes. The fact that it is hit-and-miss almost helps matters; you know that something very good is within his range, even if he doesn't always reach it.