One might be inclined to argue that Thor—the Norse god of thunder come to earth from a parallel realm called Asgard—is, with his Wagnerian helmet and boomerang hammer, one of the sillier Marvel superheroes, until one thinks of all the others; then he seems positively ordinary. Still, he’s likely to strike you as an unlikely candidate for screen adaptation, what with his antiquated mode of speech and convoluted history, which involves being transformed into a crippled human surgeon.

In the event, the screenwriters have done probably as good a job as possible buffing away the oddities and turning the story into something that contemporary audiences might swallow for amusement’s sake, though comic book purists might object to some major omissions and simplifications. In their version, Thor (Chris Hemsworth, cutting a properly striking figure) is raised by his father Odin (Anthony Hopkins, in the full stentorian mode that’s become a commonplace of him) to be his heir, making his brother Loki (Tom Hiddleston) envious. But there’s a problem. Thor is arrogant and reckless. And when he defies his father’s orders and attacks the alternate world of Jotunheim—here a realm of frost giants, headed by King Laufey (Colm Feore), that Odin had earlier defeated—after Laufey had sent a stealth force into Asgard, threatening the fragile truce between the two kingdoms, Odin strips his son of his powers (and his hammer) and exiles him to earth to learn humility and compassion.

And so it is that after a half-hour of high-octane action on Asgard, “Thor” becomes a relatively light-hearted fish-out-of-water tale, largely devoted to his interaction with a couple of out-of-the-mainstream scientists, Jane Foster (Natalie Portman) and Erik Selvig (Stellan Skarsgard) and their goofy assistant Darcy Lewis (Kat Dennings), which trails off into his effort to retrieve his hammer, which Odin has lodged, like Excalibur in the Arthurian romances, in a stone in the desert, to be extracted by the right person (Thor, of course) after he’s learned his lesson. That brings him up against the agents of SHIELD headed by Agent Coulson (Clark Gregg), but they prove a relatively benign group.

Far nastier is Loki, whose secret background and present machinations take over in the last act. He sends a giant robot to deal with Thor on earth—just think Gort on steroids—and afterwards has a knock-down, drag-’em-out with his brother back in Asgard, proving his mettle to Odin. But by that time he’s sweet on Jane, and the thought of being separated from her troubles him.

The saving grace of “Thor” is that while under Kenneth Branagh’s direction the movie has a certain stateliness (and represents a significant improvement over his work on another mythic tale, “Frankenstein”), it doesn’t take itself seriously. It’s designed as an exercise in hokum, with plenty of tongue-in-cheek moments, and can be enjoyed on that level. In that respect—and visually, too, in the design of the Asgard sequences with their glossy, brightly-lit images—it recalls Mike Hodges’ “Flash Gordon,” down to the four fighting buddies of Thor’s (played by Ray Stevenson, Tadanobu, Josh Dallas and Jamie Alexander with much the same attitude of winking conspiracy that Brian Blessed brought to the earlier movie). Hemsworth proves a likable sort, managing the transition from lordly braggart to Mr. Sensitivity without overdoing it, and he certainly has the physique for the part.

The one element of the movie that really doesn’t come off is his growing affection for Jane, which Portman reciprocates in a performance of spunk and energy. Hiddleston makes a reserved, steely antagonist, managing to keep us guessing about his motives and plans, and Skarsgard gets a lot of mileage out of the role of skeptic, as does Dennings out of hers as a dippy co-ed. And though encased in makeup, Feore brings cartoonish menace to King Laufey.

Technically, though the effects in “Thor” are no doubt state-of-the-art, they hark back to an earlier age. The giant creature Thor battles in Jotunheim could be the sibling of the Venusian Ymir Ray Harryhausen created for “Twenty Million Miles to Earth” back in 1957, and as already mentioned, the metallic Destroyer seems like Gort reborn. It’s as though the CGI were put in the service of visual nostalgia. The picture was shot in 3-D, and Branagh is smart enough to use it in a cheap way, keeping the action fairly clear (though the dark Jotunheim sequences are less successful in that respect).

One doesn’t go to a picture like this expecting any depth, and it certainly doesn’t provide it. But it’s one of the better examples of the goofy live-action comic book that’s come around recently.