Critics sometimes dismiss fantasy genres as mere escapism, and it’s true there’s nothing quite like total immersion in a magical cinematic vision to offer a couple of hours’ respite from gruelling reality. Alas, Marvel and DC universes have lately saturated the market in such a formulaic, unadventurous way you might be forgiven for assuming that AI – the most emotive sticking point in Hollywood’s recent WGA and SAG-AFTRA strikes – had already supplanted genuine human creativity.

But all is not lost! Just as recent lacklustre visits to Asgard or Atlantis or the Quantum Realm may have tempted you to swear off fantasy worlds for the foreseeable future, along comes Hayao Miyazaki to restore the faith. Studio Ghibli’s animation genius had previously announced his retirement, so we must be grateful he decided to bless us with one last masterpiece. The Boy and the Heron is the sublimest plunge into an otherworld since the same director’s Spirited Away (2001), all of it lovingly hand drawn and infused with the spirit of its creator, using CGI as a tool to enhance rather than shape the imagery – which is how it should be.

At first glance, the original Japanese poster – a blue and ochre sketch of a heron’s head – seemed benign. Bland, even. But this was before I clocked a visual ambiguity, an example of the rabbit-duck illusion made famous by Ludwig Wittgenstein, who wrote about it in Philosophical Investigations. Duck or rabbit? It all depends which way you look at it. The more I stared at the Ghibli poster, the more it didn’t look like a heron at all, but the head of a snake with a forked flickering tongue. There are no snakes in Miyazaki’s film (for which this ophidiophobe was thankful) but this possibly accidental illusion was enough to convince me that The Boy and the Heron wasn’t going to be an excursion into your average cinematic wonderland.

The action in popular fantasy worlds such as JRR Tolkien’s Middle-earth or George RR Martin’s Seven Kingdoms takes place exclusively within those worlds, mixing and matching elements from a romanticised pre-industrial medievalism with mythical creatures such as wizards, dragons and orcs. In the books, such stories usually come equipped with maps, as if to lend verisimilitude to the fabulations (and incidentally inspiring generations of children, like me, to draw maps of their own fantasy worlds; my “Land of Sweets” was right next to “Backwards Island”). The topography of Martin’s A Song of Ice and Fire was gloriously animated in the mesmerising opening credits to HBO’s Game of Thrones, varying each week according to which parts of the Martinverse were to be featured.

Such stories appeal to a sort of collective nostalgia for a time before technology got its teeth into everyone, and also frees their creators from having to worry about anachronism. They can also ignite passionate debate about sexism (“did there really have to be so much sexual violence in Game of Thrones?”) and racism (“how dare they cast Idris Elba as Heimdall in the Thor films?”)

But there’s another branch of fantasy, one that takes care to plant a foothold in a real (albeit fictional) world before pitching its characters into the magical one. The Boy and the Heron falls into this category, starting as it does in Tokyo, circa World War II. After twelve-year-old Mahito’s mother is killed in a fire, he moves with his father to a rural region of Japan, where the grieving boy finds himself harassed by a malicious heron. (Spoiler: there’s more to the heron that meets the eye, but rest assured it doesn’t turn into a snake.) Exploring the woods surrounding his new home, Mahito will find a mysterious old house which proves to be the gateway to another dimension, where his adventures will teach him life lessons.

There’s a fascist army of man-eating parrots

But this is no didactic screed, nor is it a rote, Joseph Campbell-style heroic journey in the pulp serial tradition of Star Wars. Mahito’s exploits are imbued with rich and resonant visual wrinkles. I thought I detected echoes of Arnold Böcklin’s cypresses, Giorgio de Chirico’s colonnades and René Magritte’s boulders, and there’s a fascist army of man-eating parrots, every bit as dangerous as Alfred Hitchcock’s birds, but a lot funnier. It’s a deliciously unpredictable narrative that nevertheless pays lip service to the conventions of magical fiction. The house acts as a portal, much as the wardrobe leads to Narnia, or Platform 9¾ leads to Hogwarts School of Witchcraft and Wizardry. Characters from the real world reappear in the magical one, but transformed: an ageing servant resurfaces as a dashing female pirate, just as Dorothy meets doppelganger variants of family and neighbours in The Wizard of Oz (1939).

Miss Gulch the Toto-hating neighbour, or the Wicked Witch of the West? It’s the rabbit-duck “aspect perception” all over again. Wittgenstein deemed the illusion a metaphor for describing two different ways of looking at the same thing, just as you can emerge from immersion in a magical fiction with a fresh way of looking at the real world. Sometimes the duck is a rabbit, or the rabbit is a duck. And sometimes the heron is a snake.

Anne Billson is a film critic, novelist and photographer