The Kid Who Would Be King ★★★½

Joe Cornish’s long-awaited and largely delightful follow-up to “Attack the Block” is a unicorn of a children’s fantasy movie: It’s imaginative, it’s heartfelt, and it never feels like it’s trying to sell you anything more than a measure of hope for the future. Cornish may bite off a bit more than he can chew by trying to reinvent Arthurian legend as an epic, ultra-contemporary adventure for the kids of Brexit-era Britain, but the guy hasn’t been able to direct anything in more than eight years, so it’s hard to fault him for an excess of pent-up ambition (especially not when the least effective parts of his movie involve a crazed Patrick Stewart running around in a Led Zeppelin t-shirt).

“The Kid Who Would Be King” may not be the equal of its influences, but even its awkward second act is sprinkled with a palpable degree of practical magic; even its thinly sketched young heroes are performed with rare charm. And while these backhanded compliments might read like the work of a critic hedging his bets, Cornish’s film is ultimately redeemed by its modesty — by its conviction that saving the world doesn’t (or can’t) require you to solve all of its problems.