Emerging as a sort of "Sin City Jr.," the comic book stylings of "The Adventures of Sharkboy and Lavagirl in 3-D" make for an often imaginative though less than magical family feature.

Rodriguez, who first made audiences don the funny glasses for "Spy Kids 3-D: Game Over," works with the latest technologies and teams of visual effects and digital design houses to deliver the end product, which ultimately has the pleasantly clunky charm of a very elaborate show-and-tell project.

The kiddies should still enjoy themselves, provided they don't lose their glasses, generating respectable though likely not franchise-worthy numbers.

Shaping his son's "stories and dreams" into a screenplay, Rodriguez, officially credited along with his brother Marcel, has created a " 'Wizard of Oz'-type" scenario involving a 10-year-old boy named Max (Cayden Boyd) who deals with taunting classmates and his unhappy parents (David Arquette and Kristin Davis) by escaping into a vivid fantasy life.

It's the only place one can find Planet Drool, home to Sharkboy (Taylor Lautner), a lad who was lost at sea and raised by sharks, growing up to become half-boy and half-shark, and Lavagirl (Taylor Dooley), a young flame fatale with a particularly hot touch.

But one day at school, Max makes believers out of the skeptics when Sharkboy and Lavagirl show up in Mr. Electricidad's (George Lopez) class, needing Max's assistance back on their home turf, where the villainous Mr. Electric (Lopez again) is plotting to forever do away with all manner of dreaming.

Will Max be able to save the day? Or is it just all one big dream?

To answer those questions, Rodriguez has created a wondrous theme park of a greenscreen universe, complete with wild roller coasters, aggressive Plug Hounds and the extremely gooey Land of Milk and Cookies, not to mention vivid Trains of Thought and Streams of Consciousness.

Despite those whimsical touches, the 3-D aspect is fairly unremarkable, and the plotting is definitely on the undernourished side. At its most substantial, the picture suggests a more cost-effective "Polar Express."

Handling their various roles with conviction, the spirited young cast keeps everything grounded. Lopez, meanwhile, doesn't seem to be in his comfort zone playing diabolical heavies.

Behind the scenes, the ever-multitasking Rodriguez -- he also receives producer (along with his wife, Elizabeth Avellan), cinematography, editing and composer credits -- applies his usual creative stamp while achieving the requisite out-of-this-world look with the help of a virtual who's who of effects outfits, including Industrial Light + Magic, KNB EFX Group, Cafe FX, Hybride Technologies, the Orphanage, Amalgamated Pixels, Hy*drau*lx, Intelligent Creatures, R!ot, Tippett and Rodriguez's own Troublemaker Digital Studios.

There's sad news to report about The Adventures of Sharkboy and Lavagirl in 3-D : Put on the cardboard glasses, and you can still see the movie.

Despite serving up a yummy-sounding banana split boat to transport its young adventure-seeking cast, it still has that unmistakable cardboard taste.

It's the latest from Spy Kids director/co-writer Robert Rodriguez, just coming off Frank Miller's Sin City . Now there's a movie that would have been really fun in 3-D — but no. Dominated by three child actors without discernible screen personalities, Sharkboy is just one more yarn about a kid with an unhappy home life (dad's a flaky dreamer) who concocts his own fantasy existence.

Bullied by school kids, young Max (Cayden Boyd, nice-looking chap) imagines Sharkboy (Taylor Lautner) and Lavagirl (Taylor Dooley) — her pinkish hair suggesting a rock guitarist out of Akron. Both come to life for real and whisk off Max to the endangered Planet Drool.

There, the kids float in boats down the Stream of Consciousness, traverse the Land of Milk and Cookies and meet a threatening alarm-clock-with-a-face named Mr. Electric (George Lopez, who has multiple roles). Mostly, it's labored, though one good bit is a movie natural: A narrow footbridge of ice and snow high above a perilous drop melts from each step of Lavagirl's literally torching tootsies.

The sepia-toned fantasy black-and-white scenes are in 3-D, but the rest of the movie isn't, which gives a welcome rest to the eyes. As in the '50s, the optical novelty wears out its welcome fast.

And compared with a new, more elaborate Jaws DVD coming out Tuesday, Sharkboy seems more like bait. As for Sharkboy's partner in fantasy, let's hope she'll remain a youngster forever. Otherwise, she'll need to prepare for all the C-list pickup lines in college bars that endlessly play off the Fahrenheit of her name.