Prince charming: "The Kid Who Would Be King"

Here's a funny thing: Joe Cornish, the tall, skinny one who made skits with plush toys on The Adam & Joe Show, has spent a small number of 20th Century Fox's millions on making a Brexit movie for kids. (This follows 2011's action-comedy Attack the Block, where Cornish pitched an alien invasion into inner-city tensions that preempted that summer's London riots.) Arthurian legend would appear to have returned to the forefront of our creatives' imagination in recent times, perhaps with good reason: it offers a vision of a kingdom "divided, fearful, leaderless", as an early line in The Kid Who Would Be King has it. The twist Cornish puts on the legend is to make the chosen one who pulls the sword from the stone and then unites warring factions against the wicked Morgana a bullied kid: Alex (Louis Ashbourne Serkis, Lorraine and Andy's very likeable son), whose walk to school from his one-parent household on Malory Lane sees him bypassing rows of closed shops, headlines reporting infighting in Westminster, and huddling homeless people. Faced with the responsibility of banishing evil and restoring the country to working order, our boy feels obliged to point out "I'm twelve! I'm not even old enough to do a paper round."

Cornish, for his part, is of a generation just old enough to remember the days when the output of the Children's Film Foundation - matinee timekillers such as 1970's Egghead's Robot, starring the young Keith Chegwin - was still a mainstay of the British cinema circuit; some of that influence has clearly lingered. Initially, Kid can seem a touch constrained. It's a small enough production for real care and attention to have been lavished on its visual effects: trees that uproot themselves to fight Alex and his pals, skeletal warriors, a young Merlin (Angus Imrie, a potentially great screen eccentric in the making) who shapeshifts into first a moulting owl, then an equally dishevelled Patrick Stewart. Yet the live-action, analogue scenes have a distinctly televisual look, doggedly staking out the backstreets of Harrow. (You can see immediately why the film nosedived upon its US release last month: it's self-evidently the product of a country looking in the mirror, talking to itself, fighting its own battles.) Once it leaves the suburbs behind, however, setting out on a thinly disguised Megabus down Tintagel way for a second act training mission, the film expands beyond modestly diverting and starts charming our socks off.

I began beaming around the time of the Adam Buxton cameo, and the smile didn't leave me through the raid on a seaside amusement arcade ("Cameslots") to fund a shopping spree for armour, and grew wider still during the journey to the centre of the Earth - lair of this version's Morgana (Rebecca Ferguson, ever the signifier of budgetary limitation, but more interesting as a vengeful harpy than she's ever been as a love interest) - with its fun Marcus Rowland production design. Perhaps there's an element of overreach in the way it shoots past the logical CFF ending (which arrives bang on the 90-minute mark) and onto a full-on VFX fest come the actual final reel; Fox (and possibly Cornish himself?) may have conceived of this as a project bigger than its natural shape. If nothing here has the grabby, ready-made cult appeal Attack the Block possessed in spades, the storytelling carrying everyone from A to B is far more consistent and better developed than it was there: a decade of script-doctoring in the Hollywood saltmines has served Cornish well. There will be less satisfying movies around to take your youngsters to this half-term, or to discover alongside them after it's been shunted onto the streaming services - and who knows, maybe one of those youngsters will be the one to lead us out of the state we're in?

The Kid Who Would Be King is now playing in cinemas nationwide.