Aquaman: Finally a superhero with the looks and attitude of a forgiving bouncer

When the young Willem Dafoe was doing gender-fluid Aeschylus above a sweatshop in SoHo, he can hardly have imagined that, in his vintage years, he'd find himself delivering cod Shakespeare while riding a hammerhead shark.

Such are the wonders to be encountered in James Wan’s attempt to make a Captain Birdseye origin story on the scale of an Old Testament epic.

You will rub your eyes often. Sometimes you will do so when awoken by a cruelly loud underwater explosion. On occasion you will do so after being unexpectedly impressed by a worthwhile lunatic flourish.

Indeed, the opening offers one of the best half hours in the (groans!) DC Extended Universe. That’s a low bar to clear, but it does so with metres to spare.

One evening in the mid 1980s, a lonely lighthouse keeper (Temura Morrison) encounters an exotic sea woman washed up on the rocky shore. She is Atlanna (Nicole Kidman), the exiled princess of Atlantis, but she is sufficiently comfortable on land to charm her rescuer, tie the knot and start a family. Their only child Arthur will grow up to be Aquaman (Jason Momoa).

This prologue is a strange beast. The computer boffins have created a version of younger Kidman as she might look if – how can I put this delicately? – she had aged into the current version with no outside assistance. She looks almost nothing like the real Kidman of 1985.

Anyway, those scenes are genuinely touching, and Aquaman's early adventures romp along with a carefree abandon we have, in the DC Universe, so far seen only from Wonder Woman. He beats up a submarine. Fans eager for a selfie accost him.

It looks as if we’ve finally got what we’ve long asked for: a superhero with the looks and attitude of a forgiving bouncer in a Venice Beach heavy metal bar.

Then the sub-Thor mythological stuff begins and the superstructure judders. There’s only so much fabulous maritime vulgarity a chap can handle, and Wan exceeds the average human limit sometime before the first hour is up.

Here’s Patrick Wilson on a giant seahorse. Here’s an octopus playing eight drums. It’s as much fun as it sounds until it definitely isn’t.

The picture would be less wearying if the two leads had a little more juice in their tank. Sad to relate, Momoa and Amber Heard, who plays further Atlantean royalty, are, even when caught in extreme close-up, rarely the most interesting objects on the screen.

The ecological warnings are dispatched with indecent haste. The dialogue so often suggests the original Power Rangers that you find yourself surprised the words match the mouth movements.

And yet. After the portentous yawns that were Justice League and Batman Vs Superman, Aquaman feels almost like a breath of fresh sea air. That's as much as we could hope for.

Opens December 12th