Aquaman review: This fish stew of a superhero movie is certainly an improvement on Justice League

James Wan’s film is rousing fare, made with enough conviction for it to get away with its moments of extreme kitsch silliness

Dir: James Wan; Starring: Jason Momoa, Amber Heard, Nicole Kidman, Patrick Wilson, Temuera Morrison. Cert 12A, 143 mins

Aquaman is the cinematic equivalent of bouillabaisse – a fish stew of a superhero movie into which every available ingredient has been thrown. Bits of it are hard to digest, bits are flaky, but it has plenty of flavour. Much of the film takes place underwater. There are fighting crabs, drum-playing octopuses, growling leviathans and head-banging sharks. Director James Wan (best known previously for his horror movies) somehow manages to turn this briny yarn into a full-blown Arthurian epic. It is rousing fare, made with enough conviction for it to get away with its moments of extreme kitsch silliness. The film is certainly an improvement on Batman vs Superman: Dawn of Justice and Justice League, earlier DC “extended universe” movies in which its main character also featured.

The story opens on a stormy night in Maine in 1985 as lighthouse keeper Thomas Curry (Temuera Morrison from Once Were Warriors) spots a stranded mermaid-like woman on the rocks. This is the beautiful Atlanna, Queen of Atlantis (played by a very youthful looking Nicole Kidman). She has fled her home kingdom to avoid an arranged marriage. Once she has eaten the lighthouse keeper’s goldfish, overcome her suspicion of his labrador and her distrust of the TV (at which she throws her trident), she falls head over tail in love with him. “I was the product of the love that never should have been,” Arthur/Aquaman (Jason Momoa) tells us in a voice-over.

As if to show to show they are not just taking their cue from old DC comics, the filmmakers throw in early references to sci-fi writers Jules Verne and HP Lovecraft. The screenplay also sketches in Arthur’s back story and that of the lost kingdom of Atlantis. We see Arthur as a kid, communing with a Great White shark at the Boston Aquarium. In elliptical flashbacks, he is shown being taught warrior skills by his Merlin-like mentor, Nuidis Vulko (Willem Dafoe). The filmmakers answer some of the nagging questions that audiences are bound to ask. The “high born” from Atlantis can indeed breathe both air and water. They may not have gills or fins but move easily between land and sea. “I can talk underwater too – that’s awesome!” Arthur exclaims when he discovers he shares their powers.

As a grown man, Arthur is a hulking, very hairy figure, covered in tattoos; he looks like a Hells Angel, drinks plenty of beer and has a redneck sensibility. He is also laidback and very sweet-natured. When he is not making underwater rescues of stranded Russian submarine sailors, he hangs out in the local sea-front bar with his beloved father and poses for selfies with the locals. Arthur is a “half breed”, part human, part Atlantean, and feels a bit sorry for himself as a result. When the mysterious, flame-haired warrior princess Mera (Amber Heard, dressed in a green jump suit and looking like Jane Fonda in Barbarella), tries to summon him underwater to stop the Atlanteans from attacking the “surface” world, he refuses. “Trust me, I am no king,” he says, trying to brush her off.

Occasionally, Arthur’s behaviour is baffling. He needlessly makes a lifelong enemy out of pirate Black Manta (Yahya Abdul-Mateen II). When first pitted against his scheming stepbrother Orm (Patrick Wilson), who calls him “my mother’s bastard”, Arthur acts very rashly.

The filmmakers are keen to display their eco-credentials. The human beings have been polluting the oceans, sending their nuclear submarines too close to the marine world and therefore deserve some retribution. Their behaviour gives Orm the excuse to try to wage a war against them. Cue some tidal waves and typhoons and much anxiety from media commentators about climate change.

Midway through the movie, for no particular reason other than that it brings them closer to antiquity, Arthur and Mera decamp to Sicily. They’re ostensibly there as part of their quest to find the missing trident that only the true king of Atlantis will ever be allowed to wield. There’s a strange interlude in which a Roy Orbison love song is heard at full volume on the soundtrack as Aquaman and Mera become ever more enraptured with one another. Amber Heard camps it up entertainingly as the resourceful underwater princess bewildered by human customs. (She doesn’t know whether to sniff or eat the flowers.) She and Aquaman travel by air, water and sea – and even end up briefly in the middle of the Sahara desert.

Black Manta is after them. He may be wearing kit that makes him look like a Mighty Morphin Power Ranger but he has some lethal Atlantean weaponry at his disposal. Like most villains in franchises like this, he is also very hard to kill off.

The film is promiscuous in its borrowings. The director and his screenwriters draw on Pinocchio as well as on Arthurian myth. It would be no surprise if the production design (all those barnacle-covered old sculptures and underwater cities) turned out to be partly inspired by Damien Hirst’s exhibition of Treasures from the Wreck of the Unbelievable. The internal politics of Atlanteans are even more fishy and Byzantine that those depicted in Game Of Thrones. Several rival kingdoms, each very suspicious of one another, co-exist in uneasy peace. Orm (who is as devious as Loki in the Marvel movies) is trying to trick and bully his rivals into joining the war against the humans when all he really wants is to seize power himself.

The underwater special effects are ingenious. It really does seem that the Atlanteans are chattering away many fathoms below the surface when you think, by rights, they should be gargling. The puffed-up costumes are elegant and somehow keep their shape in spite of the water. Wan does well with the fight scenes too. Antagonists hurl tridents at each other in a ceremonial “ring of fire” or engage in ferocious massed battles by the sea bed. Aquaman can be blasted and nuked but, like Tyson Fury, he always gets up from the canvas before he can be counted out. Momoa’s self-deprecating performance may sometimes verge on buffoonery but it undercuts the portentousness that might otherwise have sunk the movie.

This oceanic-obsessed yarn could easily have been a soggy anticlimax. Instead, it turns out to be one of the most energetic and likeable of the recent DC adaptations. At a time when Batman and Superman are showing signs of rust, it’s left to Wonder Woman and Aquaman to freshen the superhero universe up.