In the make-believe middle-ages of the children’s tale “Jack and the Beanstalk,” it’s highly unlikely that anyone ever said, just before attempting some feat, “I got this.” But it’s this little anachronism — a slight nod to modernity without pushing it too far — that makes the updated tale of “Jack the Giant Slayer” a breezily enjoyable blast of sword-wielding fantasy.

Nicholas Hoult (the zombie teen in “Warm Bodies”) is Jack, a good-hearted peasant kid orphaned at a young age and in the care of his uncle (Christopher Fairbank). Forced by poverty to sell their horse at the market, Jack ends up trading it for a handful of magic beans from a mysterious monk. This is also where he unwittingly rescues the local princess, Isabelle (Eleanor Tomlinson), from some local ruffians who don’t realize who she is. Of course, he’ll have more chances to save her later.

Back home, uncle doesn’t care about beans and princesses, so he tosses the beans away while reading Jack the riot act. Big mistake. Once exposed to water, these beans explode skyward with huge, coiling stalks that lead to the world of the giants — who’ve just been waiting to wreak revenge on humanity for a defeat so many ages before that people thought it was just a legend.

Director Bryan Singer (“The Usual Suspects,” “X-Men”) keeps things moving briskly, and he’s helped along by a solid cast that includes Ian McShane as the king, Ewan McGregor as his loyal foot soldier Elrond, and Stanley Tucci as the vile and ambitious Roderick, a man who thinks he can harness the power of the giants to make himself king.

But the real star is the technology, which turns actors Bill Nighy and John Kassir into the two-headed giant leader General Fallon. Though it sometimes seems as if the perspective is a little odd — the film is in 3-D, which it doesn’t really need — the worlds of the rampaging giants and the Lilliputian humans mesh well.

“Jack the Giant Slayer” may be too intense for the youngest viewers. While there’s no gore, all the humans being stomped and eaten isn’t exactly the stuff of sweet dreams. Yet Singer keeps a light touch, never straying too far from the source story’s sense of whimsy while keeping mind that at heart this is also a love story between a boy and a princess.

Unlike Peter Jackson with the overstuffed “The Hobbit,” Singer shies away from the epic and settles for entertaining.

Sometimes that’s more than enough.