Fairy-tales are in this year, both on the small screen (“Once Upon a Time,” “Grimm”) and on the large one—and not merely in the usual animated format. “Mirror Mirror” is just the first of two live-action takes on the Snow White story coming out in 2012 (though it does employ computer animation to set the stage in an introductory prologue, and plenty of CGI elsewhere as well).

The movie has the visual extravagance typical of the work of director Tarsem Singh Dhandwar (the wondrous journey through the titular mirror is an obvious example), but not to the same extent here as in “The Cell” or “Immortals,” and to far more genial purposes. This version of the old tale is a broad, farcical one, in which Julia Roberts is given full latitude to vamp it up as the Evil Queen while being seconded by mug-master Nathan Lane as her bumbling aide. Meanwhile the story of Snow (Lily Collins) plays out in the nearby woods as the beauteous lass is befriended by the seven dwarfs and is romanced by her prince charming, here a bumbling but devoted fellow played by Armie Hammer.

The big problem with “Mirror Mirror” isn’t that it remakes the old story in terms that might appeal to modern audiences accustomed to hip irony. That’s to be expected. The difficulty is that in doing so, Tarsem and his scripters struggle to find the right tone and never quite succeed, instead trying to juggle different approaches. On the one hand, there’s the Roberts-Lane material, which is reminiscent of a Disney flick. But Roberts is no Glenn Close, and her Evil Queen no Cruella De Vil; there’s more than a hint of campy dress-up to her performance, and beside her Lane comes across as a live-action version of one of the animated household implements from “Beauty and the Beast.”

Beside this we’re given some comic-action stuff in the material involving the dwarfs, in this case portrayed as a gang of lovable rogues who survive by robbing passersby in the woods. With new names (Napoleon, Half-Pint, Grub, Grimm, Wolf, Butcher and Chuckles), they dress in camouflage gear and wear balloon-like stilts to appear gigantic. And they engage in rowdy camaraderie that’s about as juvenile as the stuff that used to bless old Bowery Boys grindhouse fare. Of course the script tries to build sympathy for them by revealing that they’re outcasts—but in trying to paint them as lovable rogues only manages to achieve the roguish part, not the lovable quality.

This section of the picture also involves the septet’s training Snow in combat technique, eventually turning her into a petite warrior princess who can wield a sword with dexterity. Of course it wouldn’t be possible, in this day and age, to present a heroine who doesn’t have the power to do battle with anybody, whether it be the prince or a gigantic CGI beast that emerges in the last reel.

Which takes us to the last thread in the picture—a propensity to throw in grotesque elements that sit uneasily with the farce or Hammer’s goofy slapstick. There’s a sequence near the start, where the queen gets a beauty treatment that includes, among other things, being smeared with bird excrement, that’s meant to be funny but comes off revolting. In a Kafka-esque moment Lane is transformed into a cockroach. An extended fight scene—with overtones of Harryhausen—features a trio of huge wooden marionettes that clatter and (I think) giggle as they try to massacre Snow and the dwarfs until their strings are severed. And there’s that final, prolonged encounter with the queen’s giant beastie, which feels like standard action-comedy filler, though it must be admitted that the CGI is pretty good.

The result of all this is a rather muddled modernized fantasy that never manages to find a coherent style. In its favor, Collins makes a pert heroine, if not an especially distinctive one, and Hammer exhibits some unexpected comedic chops (at times one could mistake him for John Krasinski), even if some of the goofy routines he’s compelled to undertake (like a “puppy love” bit) are pretty embarrassing. Some of the actors playing the dwarfs come off well, too, especially Jordan Prentice as serious, reasonable Napoleon. (Ronald Lee Clark, on the other hand, is a trifle creepy as Chuckles, though the fault is more with the character than with him.)

Technically the picture is variable as well. On the one hand Tom Foden’s production design and the art direction overseen by Ramsey Avery and Isabelle Guay are impressive, and Brendan Galvin’s cinematography certainly takes advantage of their gaudiness. On the other hand, the late Eiko Ishioka’s costumes go overboard in oddity, looking like something out of a Tim Burton movie—“Alice in Wonderland,” for instance—gone to seed. Alan Menken’s background score is surprisingly generic.

One can sense what Tarsem and his colleagues were after in “Mirror Mirror,” but also how far they are from having achieved it. In the end the picture it winds up most recalling is Roman Polanski’s “The Fearless Vampire Killers,” which also gave a new spin to an old genre. The difference is that it was more sophisticated, and a good deal more amusing.