iri is a lively yellow dinosaur, Lou is an amiable purple palorchecie (a fictional beast, vaguely resembling a palorchestes, which in turn vaguely resembles a giant tapir) – and if you've been watching their CBeebies show, which hails from New Zealand and consists of 5-minute episodes, you'll know they're the best of friends despite their ingrained temperamental differences. But how did they become friends in the first place? For the uninitiated, Kiri and Lou Go Raaa! functions as an introduction to the characters and their world, while for fans it's a delightful origin story.

At only one hour long, the runtime is toddler-friendly – and to be honest, there are plenty of films marketed at adults that could learn a lesson from writer-director Harry Sinclair's economical storytelling. (Sinclair is also the writer of the TV series, alongside Buffy the Vampire Slayer writing alum Rebecca Kirshner.) With the voice acting talents of Olivia Tennet (Freda in Lord of the Rings: The Two Towers) and Jemaine Clement (Flight of the Conchords), plus dreamy songs from Don McGlashan (Blam Blam Blam, The Front Lawn), Kiri and Lou Go Raaa! would arguably work superbly as an audiobook or radio show – except the visuals are a treat too.

It's a cliche to bang on about the fingerprints in the modelling clay, as if effort and a handmade aesthetic automatically equate to great storytelling, but in this case, the tactile quality of the animation does help underscore the gentle perils of the duo's various adventures. There's the sense that they aren't just computer sprites existing in some nebulous cloud, ergo they actually could be washed away in the sea, or melted by a "smoky mountain". And there's a wholesomeness to stop-motion that's hard to beat; it's a tangible reminder of the physical world, outside screens and digital ephemera. Co-director Anthony Elworthy's long list of credits, including The Boxtrolls, My Life as a Courgette and Kubo and the Two Strings, also functions as a whistle-stop tour of some of the best children's animation of the last decade-plus, so perhaps it shouldn't be a surprise that this big-screen adventure has turned out so beautifully.