Directed by Kenneth Branagh. Starring Chris Hemsworth, Natalie Portman, Anthony Hopkins, Tom Hiddleston, Stellan Skarsgård, Kat Dennings, Idris Elba, Ray Stevenson 12A cert, gen release, 114 min

Marvel's Norse god makes for a decent blockbuster, writes DONALD CLARKE

YOU GET THE sense that Marvel Comics is beginning to run out of properly vital icons. Both Thor and Captain America – subjects of film adaptations this summer – were mightily popular in their day. Neither retains, however, quite the resonance of Spider-Man, Iron Man or Daredevil. Cap is a bit too jingoistic. Thor is a bit too, well, confusing.

Think about it. The Thorcomic employed all the great Norse gods as characters. Thor was fiery. Loki was naughty. Odin was old and wise. Some of the action took place in Asgard, the gods' home world, but the bulk of the comic concerned itself with Thor's adventures on Earth. It's rather as if a Norwegian publisher had delivered a comic in which Jesus-Man fought Doctor Octopus on a weekly basis.

Anyway, noting the cod- Shakespearean nature of the gods’ language, Marvel has hired Kenneth Branagh – still waiting to be Olivier-in-waiting – as director for the Thunder-bringer’s first feature outing. It’s not bad.

The stuff in Asgard, what with its madly expensive but entirely predictable digital landscapes, never quite escapes the twin menaces of chain-mail camp and sub-Tolkien pomposity.

“Har! Har! Har! Foolish dwarf-maiden. The very spine of heaven quivers at my awesome wrath,” nobody really says.

However, when Thor (Chris Hemsworth) arrives on Earth, expelled after rashly overreacting to an incursion by ice beasties, the picture becomes noticeably livelier and less self-important.

Marvel fanatics will regret that the film ditches Thor’s earthly alter-ego – though frail Dr Donald Blake is coyly name-checked – but the interactions between the puzzled god and a party of hip scientists are genuinely amusing.

“I like this drink!” Thor says while drinking coffee in a diner. He then flings the cup to the ground and bellows “Bring me another!” Well, I laughed.

The action begins with top scientist Natalie Portman encountering an atmospheric aberration above the deserts of New Mexico. As the clouds rage, a body slams dramatically against the side window of her vehicle.

While emo boffin Kat Dennings and Nordic boffin Stellan Skarsgård scratch their own helpless heads, Portman stares aghast at the visitor. He is big, blond and baffled.

The film then flashes back to explain how the hero found himself expelled from the realm of the gods. Brave-but-rash Thor and clever-but-unscrupulous Loki (Tom Hiddleston), his younger brother, are eager to inherit the throne of Odin (Anthony Hopkins in full Jones-the-Lear mode).

Thor is on the point of ascending when, prompted by some baffling intrigue, he travels along a colourful bridge to launch a sneak attack against these evil ice things.

Well, despite their rough manners, the Lords of Asgard are apparently expected to demonstrate restraint, honour and all that malarkey. Thor is separated from his hammer and sent to Earth. He will not be allowed to regain his full powers until he has proved his worthiness.

Branagh and his cast take the material just seriously enough to avoid complete descent into preposterousness. The actors keep a straight face, but cheeks are ever so slightly distended by quivering tongues. Hemsworth deserves several vats of mead for making such an attractive – yet awesome – creation of the central character.

A former star of Home and Away, Hemsworth has that very Australian knack of combining physical might with amiably ingenuous charm. The scene where he and Skarsgård drink each other into insensibility reeks – insofar as such a thing is possible in this sort of enterprise – of after-hours integrity. One suspects the actors rehearsed vigorously.

So, Thorwill do well enough for the first blockbuster of the summer. One aspect of the Marvel experience is, however, becoming increasingly irritating. For what now seems like decades, Sam Jackson has been popping up in the company's films to offer supposedly tantalising pointers towards the forthcoming Avengerspicture.

You have far, far better things to do than sit through four hours of end credits to see the latest pointless teaser for the 2012 ensemble piece. The second coming has been less heavily trailed.