Oz the Great and Powerful” would probably knock ’em dead as the basis for an attraction at Disneyworld. Director Sam Raimi’s reinterpretation of “The Wizard of Oz” universe is loud, eye-poppingly colorful, and thanks to 3-D, there’s enough stuff hurtling at the audience to make you feel like you’ve stepped into a meteor shower.

But it doesn’t make for a very good Disney film. Mildly diverting and clever in spots, this “Oz” is certainly no bookend for the 1939 classic that introduced author L. Frank Baum’s fanciful adventure to a wider world.

Raimi’s prequel conceit, based on a script by Mitchell Kapner and David Lindsay-Abaire, is to tell the wizard’s origin story. So the film opens in black and white as Oz (a miscast James Franco) lives one step above criminal. He’s a low-rent Kansas magician and charlatan who gets by on the carnival circuit through charm and moxie. While on the run from the strongman and his clown sidekick for some infraction, Oz hops into a hot-air balloon, gets swept into a tornado and lands, of course, in the magical kingdom of Oz, where the film blooms into CGI-enhanced lollipop color.

He is met by Theodora (Mila Kunis), one of the witches of this kingdom, who informs him that he must be the wizard that has been prophesized to rescue them from the clutches of the one she dubs the Wicked Witch (Michelle Williams). But then he finds out that Theodora, along with her sister Evanora (Rachel Weisz), may not be telling him the truth.

Along with his new sidekicks — Finley (Zach Braff), a flying monkey with a hint of attitude; China Girl, a small girl made of china (Joey King), and a parade’s worth of tinkers, farmers, and munchkins — Oz has to man up, slay whomever is the evil one, fall in love, and live if not happily ever after, then at least live comfortably enough until Dorothy comes along.

Because Raimi (“Spider-Man”) couldn’t tread too closely to the original without infringing copyright, part of the film’s fun comes from how the well-known concepts are reimagined. There’s a lion but he’s not cowardly, there are scarecrows but they’re not alive, and the biggest Tin Man of all just may be Oz himself, who needs to find a heart.

Kudos to the technical teams that make Finley such an impressive and expressive melding of human and simian. He also gets some of the best lines. On top of that, it’s amusing to see long-time Raimi stalwart Bruce Campbell — the star of the director’s early “Evil Dead” films — in a cameo as one of the Emerald City gatekeepers.

Yet, like so many big-budget movies these days, it’s hard to care much about what’s going on, especially as the film builds to its special-effects-driven conclusion. Franco’s smirking performance doesn’t help much.

There may be enough here to keep younger children entertained, but with “Oz’s” 130-minute running time even they might get twitchy. (Plus, parents take note, the Wicked Witch’s menacing flying baboons are a little on the scary side.)

“The Wizard of Oz” certainly deserves a better successor. But the amusement-park ride will be awesome.