After helping save the world from the alien Steppenwolf in Justice League, Arthur Curry (Jason Momoa) returns to a life of fighting crime and saving innocents on the open ocean. When his half-brother Orm (Patrick Wilson) sets plans to become the “Ocean Master” of Atlantis and invade the surface world, Arthur is convinced by the princess Mera (Amber Heard) to travel to Atlantis and claim the throne for himself – and in doing so, prevent war with the surface world.

Aquaman is one of the more challenging superheroes to translate to live-action cinema. He is a comic book superhero, so must be able to smoothly slip into an ensemble of city-based urban characters. At the same time he spends much of his time in Atlantis, a high-technology wonderland beneath the ocean. That wonderland, however, comes with rival kingdoms, sea monsters, magic, and any number of ancient legends, myths, and prophecies. Be a superhero adventure, be a science fiction story, be a fantasy epic; only Marvel Studios’ Thor movies have probably had it so hard. There is also the problem that, of the most popular characters between publishers DC and Marvel, Aquaman is likely the most widely mocked. He is, after all, a man who swims really fast and talks to fish.

In an over-saturated market – 2018 had at least nine separate theatrical releases based on superheroes – Aquaman does not quite surpass all of the challenges facing it, but my goodness Warner Bros and director James Wan give it a red-hot go. This film is an unexpectedly huge amount of fun, and where it gets a little too silly or over-the-top it always has Jason Momoa to wink at the audience and remind them not to take things too seriously. For fans of the comic book it comes with a lot of nods and gestures to pre-existing characters and places. For the fresh viewer those references all included so smoothly that it doesn’t matter if you know your Orm from your Vulko, or the difference between Atlantis and Xebel. Even if you do not quite follow a moment of the plot or understand a particular character, it does not matter: something else will come along within the next 30 seconds. The aim of Aquaman, as far as I see it, is to throw as much onto the screen as humanly possible and simply pray that enough viewers see something in the Pollock-like result that tickles their fancy. For some that will be seeing one of their childhood favourites finally take centre-stage in a movie (I was a big Superfriends fan as a kid). For some it will be the visual effects (this film has so much CGI it’s effectively a cartoon). For what I suspect is a fairly large proportion of the audience, it will be Momoa’s glistening chest. This is one big mess of a film, but there’s so much to enjoy among the debris that I challenge you not to find a good time somewhere inside.

The visual effects arguably have eyes bigger than their budgets. Underwater scenes include every character with hair having to have it computer-generated; a technique that seems to occasionally shave the top inch off some characters’ heads. The non-humanoid creatures of the deep are innovatively designed but sometimes not perfectly executed. I prefer the ambitious attempt to a conservative success. This is a film for which the tie-in art book should look superb.

The bleak, operatic tones of earlier DC movies like Man of Steel and Batman v Superman have been dropped in favour of a scene-by-scene combination of disaster movie, dynastic war movie, undersea adventure, and Raiders-style tomb raiding. The zig-zagging narrative is held together by a fairly consistent comedic tone, and charismatic performances from a range of characters. Momoa and Heard have a great chemistry together, and an amusing rapport. Mera does suffer somewhat from gratingly typical Hollywood problems, which lets down what is mostly a great pro-active character. For one thing she’s required to fight bad guys and swim through the ocean in high heels. For another, small guest appearances by Nicole Kidman aside, she’s effectively the only woman in the film. Hollywood can and should do better than this.

As King Orm – known as the Ocean Master in the comics – Patrick Wilson brings an appropriate level of camp. The real stand-out in both performance and design is Yahya Abdul-Mateen II as Black Manta. Clad in black body armour with a ridiculous oval helmet that shoots energy beams, he is one of the most accurate translations from page to screen I can remember seeing. Often a superhero film struggles to accommodate multiple villains; Aquaman balances Orm and Manta wonderfully.

The supporting cast is strong and reliable, including a few famous names like Temuera Morrison and Willem Dafoe. I feel compelled to specifically call out Dolph Lundgren as Mera’s father and ruler of neighbouring kingdom Xebel. Lundgren is a rock-solid actor who, likely due to his prominent Swedish accent, never seems to get offered the roles of which he’s capable. He was great as former boxer Ivan Drago in last month’s Creed II, and now he makes an entertaining showing here. Hopefully this foreshadows further Hollywood roles in 2019 and 2020. God knows he deserves them.

The production design, while haphazard is hugely imaginative, providing such highlights as a Tron-like entry into a neon-lit Atlantis, a superb run-and-gun fight through a Sicilian village, and a Frazetta-esque giant battle that so goofy it’s adorable. In keeping with the rest of the film, Rupert Gregson-Williams’ musical score dances all over the music store. There’s old-fashioned action music, new-fashioned action music, Vangelis-inspired electronica, and Daft Punk-inspired electronica. By the time Gregson-Williams hits the pan-pipes, you know he has to have his tongue in cheek when composing it.

Do not take this film seriously. Watch it with an open mind, and a desire to enjoy yourself. This film is everything, but most of all it’s a deliberate confection. It’s instinctively and immediately silly. It wants you to have fun, and it does a damn-good show of making that happen. Warner Bros’ attempts at a cinematic DC universe is still staggering about the place without a plan, but at least they have started doing a properly entertaining attempt at it.