This isn't what you'd expect to see after trooping into the kiddie's matinee from the Children's Film Foundation.

There are no midnight feasts, talk of lashings of ginger beer or the Enid Blyton style apprehension of ne'er-do-wells by pre-pubescent school kids.

Instead, the driving force behind this likeable comedy from Borrowers director Pete Hewitt is - how can I put this? - the breaking of wind.

Patrick Smash (newcomer Bruce Cook) has been blessed with a unique gift - he's got two stomachs (just like a cow, as his caring GP puts it).

He has just the one friend - Alan A Allen (Harry Potter's Rupert Grint) - who's pally with him because he hasn't got a sense of smell.

Patrick wants to be a spacema,n while his science prodigy pal wants to be an inventor. Harnessing Patrick's wind power and his chum's genius, they create a flying machine.

But they are destined to take separate paths after Alan is recruited by FBI man Johnson J Johnson (Paul Giamatti) to help the American space programme.

Patrick's career path is less elevated as he is dragged on tour by second best opera singer in the world, Sir John Osgood (a wonderfully overblown Simon Callow).

The trouser-filling youngster is recruited by Sir John to supply the elusive note that will make him the world's greatest - but naturally (or unnaturally), Patrick doesn't use his mouth.

If it all sounds a bit insane, of course it is. But director Pete Hewitt has managed to create a wonderfully surreal parallel universe, heavily redolent of 1950s Britain, where every car is a green Mini.

Grint is slightly irritating as the boy genius while Stephen Fry plays, well, Stephen Fry, and Cook lends a touching vulnerability to the eternally put-upon Patrick.

It's a film that has got a frighteningly accurate perception of its target audience - young children with an obsession for bodily functions. A breath of almost fresh air.

Tim Evans