This entry to the pantheon of farting films comes from Brit director Hewitt, of Bill & Ted's Bogus Journey and The Borrowers fame. It's a peculiarly quaint comedy with transatlantic ambition, which launches its schoolboy heroes from Home Counties capers to Cape Canaveral flights of fancy - all, of course, fuelled by flatulence. Gawky ten-year-old Patrick Smash (Cook) is an aspiring astronaut whose double-stomach feeds the zephyr arse which causes him such embarrassment and ostracism at school. Grint is the half-pint Barnes Wallis, a bespectacled boffin with a creepy liking for HG Wells-era iron and leather contraptions, who harnesses Patrick's bottom to power a craft in a village fair, man-powered air flight competition. Next stop, the stars? As a kids' movie overplaying its 'triumph over adversity' metaphor, this takes the biscuit. All the Heath Robinson business in council estate sheds has the naughty earnestness of Beezer comic strips of old.