After the near death experience of Justice League, it appears the thinking went something like this: the DCEU has to storm back with a movie of such crowd pleasing bravado and scale that the audience, though their brains will naturally resist, will ultimately surrender to its relentless action and a sub-aquatic succession drama modelled on proven templates, sorry hits, like Thor and Black Panther. We’ll get James Wan to direct it – a man with a sense of style who doesn’t see comic book material as a spur for bleak and tragic introspection; a man who injects his movies with colour and energy, and the 13-year-old nephew of Warners’ CEO Kevin Tsujihara, can write it, as we’ll need to cut a cost to cover the monumental all-consuming visual effects.

And there, as a better writer than me and indeed the duo hired to write Aquaman once said, is the rub. The only critically well-received DCEU flick, Wonder Woman, paired the hero with a well-bred partner and thrust them into fish out of water, pun intended, situations and action heavy scenarios. Broadly, Wan’s movie does the same, but with the series’ emphasis now firmly on fun, there’s a crude and botched attempt to invest the proceedings with a classic adventure undercurrent – a Romancing the Stone for millennials. But Aquaman’s writers haven’t the nous to plot a movie with that kind of effortless appeal.

The flick as finished, though visually impressive and endowed with likable stars in the shape of Jason Mamoa’s hulking reluctant hero and Amber Heard’s comely Atlantian, is content to be cheesy and one-dimensional when it could have pushed for greater, er, depth.

Elements teased but not developed in subsequent drafts of the screenplay, include a missed opportunity for the world’s second great ecological blockbuster (after Star Trek IV: The Voyage Home) and the original prospect of a treasure hunt with a fictional city’s antiquity as a backdrop. How much clearer and more interesting the story would have been had King Orm, bravado and little else in Patrick Wilson’s hands, been clear that oceanic pollution and the clock ticking down to marine devastation was his single aim for attacking land lubbers. His daughter might have choked on plastic, or similar, but instead residents of Atlantis simply wash the ocean and deposit all our rubbish on land (begging the question, why didn’t they do this earlier?), then plot to attack for reasons that remain nebulous. Having dangled the prospect of a modern Atlantis with a technologically advanced city atop the old, the story takes Mamoa and Heard to, er, Italy, rather than making the most of this new environment and developing the movie’s underwater mythos.

In this way Aquaman feels like a movie of missed opportunities. The elements that work least, the improbable relationship between Nicola Kidman’s queen and a dull lighthouse keeper, the barely sketched revenge sub-plot involving a pirate who inexplicably blames Mamoa for not saving his multiple-murderer Dad, are the ones given the most prominence. A sequel tease even threatens to push the pirate story centre stage, despite the film closing with the titular hero having attained an all-powerful position as oceanic head of state. The filmmakers, it’s clear, had a lot of disparate ideas. The finished flick cultivates the worst ones, seemingly afraid to challenge its audience.

There’s an in-movie acknowledgement that these DCEU movies have been produced in the wrong order, and consequently, a quick mention aside, the film ignores the larger pool of characters previous introduced and inexplicably not called upon here. This flick should go some way to putting things right in respect of a character we were asked to care about before we’d got to know him, but if the series is going to fully recover from Zack Snyder’s early assault, it will have to better marry brains with brawn, resisting the false choice of Wan’s salty blow out.