C

The mystical device at the center of “Prince of Persia” is a magical dagger that, when properly used, can reverse, as the subtitle puts it, “the sands of time,” and take the holder into the past. The time-reversal shtick is always a bad narrative crutch, since it renders everything you see subject to immediate revision and by definition drains the emotional content from the story. Just think of how “turning back the clock” ruined the close of Richard Donner’s “Superman” movie—and if the recent DVD release of his intended sequel is any indication, he hadn’t learned from the mistake and intended to repeat it.

Still, it’s entirely appropriate in this case, since watching the movie is like stepping into a tine warp to an earlier cinematic era. Though it has a video-game feel that comes from its source, “Prince of Persia” recalls nothing more than old Arabian Nights pictures. It doesn’t even boast the goofy fun that came from Ray Harryhausen’s stop-motion contributions to his Sinbad series—no giant scorpions or dancing skeletons here—or the manic strain with which Robin Williams energized Disney’s “Aladdin,” which it copies pretty slavishly in terms of plot. Except for the more advanced effects, it really hearkens back to the age of Douglas Fairbanks—and then Senior, not Junior.

The story is set in the pre-“300” Persian Empire, ruled not by the grotesque gargoyle of that Frank Miller-Zack Snyder film but by wise King Sharaman (Ronald Pickup). How wise is he, you ask? Though he already has two sons of his own, he adopts as a third a courageous orphan he encounters in a tour of his capital. Years later that boy, Dastan (Jake Gyllenhaal) is serving in the great Persian army under his siblings, the heir apparent Tus (Richard Coyle) and his more aggressive younger brother Garsiv (Toby Kebbell).

Sent out to deal with unnamed terrorists, the brothers and their forces turn their attention to the “Sacred City” of Alamut, which their uncle Nizam (Ben Kingsley) informs them is supplying the highest-grade of weaponry to the malefactors. (What subtle allusions to contemporary history!) Tus orders the huge place taken, the occasion for the first big action sequence, an assault in which the irrepressible Dastan takes the lead—and which is structured like the first level of a video game (we even get zoom-in graphics describing the gates to be targeted, though to be honest they don’t make the topography clear). The attack succeeds, and the beauteous princess Tamina (Gemma Arterton) is taken prisoner, along with that magic knife, which Dastan winds up with. But when Sharaman shows up to excoriate Tus for attacking a holy place, he’s killed by a poisoned robe that Tus has instructed Dastan to give him as a gift (you know, the same brand that killed Hercules). That supposedly identifies Dastan as a traitor, and he runs off with Tamina in tow (and that knife in his belt).

Thus begins their adventures together, which involve Amar (Alfred Molina), a rascally entrepreneur who makes a mint off ostrich races, and his aide-de-camp Seso (Steve Toussaint), an expert African knife-thrower, as well as the head of a bunch of horrible thugs called Hassasins (Gisli Orn Gardarsson), who uses huge snakes as his chosen killing machines. Lots of fights, close escapes, and turns of the old sands of time lead to the revelation of the villain behind all the machinations and his motives. (His identity will not be disclosed here, but one must issue a modest warning to filmmakers: if you want to maintain even a modicum of uncertainty about who the bad guy is, it’s really not a good idea to cast Kingsley in any role, but particularly not that of the king’s younger brother.) It all ends in a big confrontation—or series of them—in which the sands go to town until all’s well again. And we do mean all.

This is utter hokum, and it’s not played with enough brazen absurdity to make it much fun; for the most part under Mike Newell’s uninspired direction it’s done with a half-hearted smirk that keeps it totally earthbound. The movie needs the sort of zaniness that Johnny Depp brought to Jerry Bruckheimer’s previous franchise, “Pirates of the Caribbean,” the first installment of which the star raised to heights of inspired lunacy. But the only person in this cast who goes a similar route is Molina, who brings a seedy charm to the garrulous, greedy ostrich-racer Amar. Otherwise Gyllenhaal gives the old college try to the Aladdin-like Dastan, but lacks the charisma the part requires, and Arterton is lovely to look at but similarly bland. As is his wont, Kingsley happily masticates the lavish scenery with such lip-smacking relish that even the malevolent Gardarsson comes in distinctly second-best.

Bruckheimer has given the movie the full treatment, and the CGI effects construct a ludicrously enormous, multi-terraced Alamut that would put the hanging gardens of Babylon to shame, along with some suitably threatening reptiles. But the many time-shifting sequences are curiously messy, and the underground cataclysm at the close is confused and confusing.

For an undemanding viewer willing to sit back and happily put his brain on hold while scarfing down a couple tubs of popcorn, “Prince of Persia” will be a tolerable two hours’ escape from the summer heat. But what Bruckheimer’s clearly hoping for is his next franchise. And what this movie proves is that like the many attempts to identify a successor to Harry Potter—all of them failures—a replacement for “Pirates” is going to be hard to find. This certainly isn’t it, though it might spawn a successful ride at Disneyland.