It seems that director Bryan Singer can be counted on to bring a welcome measure of style, as well as simple coherence (not always something you can assume nowadays), to movies in diverse genres—thrillers (“The Usual Suspects,” “Apt Pupil”), World War II spy stories (“Valkyrie”), comic-book adaptations (the overrated “X-Men” flicks and the underrated “Superman Returns”) and now a family fantasy. While “Jack the Giant Slayer” probably tries to fulfill too many different audience expectations, it still stands tall beside Hollywood’s other recent fairy-tale adaptations.

At its heart the movie—based on a screenplay by a trio that includes Christopher McQuarrie (who wrote “Suspects”)—is a sort of homage to the great Ray Harryhausen fantasies of the late fifties. The plot, set in fairy-tale medieval times, is about Jack (Nicholas Hoult), a simple farmboy who sets out to rescue Princess Isabelle (Eleanor Tomlinson) from the land of giants in the sky, which has been reconnected to the human world below via a huge stalk accidentally grown by some magic beans. That’s not much different from “The Seventh Voyage of Sinbad,” in which the famed seaman sailed to rescue a princess from an evil sorcerer.

But of course this is the twenty-first century, the era of the computer-effects blockbuster, and so the picture has to go that route too. A lot more footage is devoted to the giants than was given over to Harryhausen’s Dynamation creatures, who appeared in relatively short segments. But it must be said that while a big budget and an army of craftsman were obviously behind fashioning the giants and their world and (with the help of some real-life actors like Bill Nighy)) putting it all in motion, there remains a hint of the crudeness that marked the old stop-motion technique, whether intentional or not. On the other hand, one might have done without the occasional crassness that, probably as a bow to the expectations of today’s adolescents, is added to the mix. (Consider, for instance, the sequence set in the giants’ kitchen, where the princess and her guardian Elmont are on the menu. The emphasis on the cook’s nasal discharge is an unnecessary intrusion, and a crotch gag is similarly gratuitous.)

But Singer and his writers add another element to the mix—a vibe reminiscent of Rob Reiner’s “Princess Bride.” That’s evident not only in the inevitable romance between commoner Jack and the noble Isabelle, which mirrors the love story between Westley (Cary Elwes) and the princess (Robin Wright) in that film and is equally sweet, but in the noble figure of Elmont, whom Ewan McGregor seems to enjoy playing as much as Mandy Patinkin did Inigo Montoya for Reiner. And then there’s Stanley Tucci, hamming it up mightily as the villainous Roderick, Eleanor’s snide and traitorous betrothed. Blink and you might take him for Christopher Guest’s Count Rugen; as Tucci’s costumed and made-up (complete with beard), they even look alike. And is it a coincidence that Andre the Giant appeared in “The Princess Bride”? Some aspects of this “Bride”-like quality misfire: Ewen Bremner is more annoying than funny as Roderick’s giggling factotum Wicke, for example, and you’re unlikely to bemoan his departure when it comes. More often than not, however, it works, and acts as a rather charming sauce to the action-adventure dish.

Hoult is much the reason for the pleasant effect. The gawky, gangly fellow who even made a zombie someone to root for in “Warm Bodies” is a likable hero again, but in far less outrageous mode. He’s nicely paired with Tomlinson, though she’s more anonymous; and Ian McShane proves a stalwart King Bramwell, whose castle comes under assault from the rampaging giants in a culminating battle sequence that, frankly, goes on too long. (Once you spend millions on the effects, after all, you don’t want to cut out too many of them.) And not a few viewers are likely to find the coda—which reveals the location of a magic crown that staves off the giants—just too cute for words.

Still, though “Jack the Giant Slayer” might have about as much connection with the venerable fairy tale as “Snow White and the Huntsman” did with its source (though more than 1962’s “Jack the Giant Killer,” which didn’t even have a beanstalk, did), it’s still a surprisingly deft, enjoyable variation on the old tale.