With so much American cinema of late designed to slap us back into juveniles, it's a blessed relief to have a movie remind us how it felt to be accelerating into adulthood.
Not that Moonrise Kingdom is a typical coming-of-age film - it is a Wes Anderson movie and a return to live action after his entertainingly eccentric stop-motion creature feature The Fantastic Mr Fox.
And as with some of Anderson's previous films, the combination of precocious kids playing off offbeat adults risks this being a quirky indulgence which will overstay its welcome. The director has had plenty of those among his career.
But Moonrise Kingdom turns out to be heartfelt, deadpan-hilarious, and sweetly melancholy. It's the sort of Wes Anderson film you don't have to like Wes Anderson films to like (or if you do, it's right up there with 1999's Rushmore).
Not that the director has pulled back from his distinctive, affected style.
Watching this, it can feel as if you are peering into the film's late summer of 1965 world through a giant moving Viewmaster into a parallel storybook world.
But here, Anderson's mannered framing and meticulous period style still allows plenty of breathing space for its love story - that of two 12-year-old runaways, Sam and Suzy (Gilman and Kara) who start out as penpals and take off together into the gentle wilds of New Penzance Island off the New England Coast.
That's after bespectacled bullied Sam goes awol from his scout camp on the island and Suzy packs her things (fantasy books mostly) and escapes the island house where her parents (an equally droll McDormand and Murray) endure a crumbling marriage while fretting about raising their brood of bookworms.
As the two young lovebirds set up camp in an idyllic cove they name "Moonrise Kingdom", their absence throws Suzy's folks, as well as the local island cop (Willis, terrific), Sam's scoutmaster (Norton, hilarious) into a panic.
That brings in "Social Services" (a typically icy Swinton resplendent in a Salvation Army bonnet) to the island too - Sam's an orphan and his foster family aren't keen on getting him back. Add Harvey Keitel and Jason Schwarzman to that ensemble and it becomes a little crowded as this heads towards an ending that does undo a little of the understated magic of what's gone before.
But for the most part, Moonrise Kingdom is a whimsical wonder.
Cast: Jared Gilman, Kara Hayward Bruce Willis, Edward Norton, Billy Murray Frances McDormand, Tilda Swinton
Director: Wes Anderson
Running Time: 99 mins
Verdict: Enchanting eccentric coming-of-age story