Narrator Charlize Theron introduces us to futuristic Metro City, a cotton-candy colored utopia floating high above the dingy, ravaged Earth, where helpful, efficient robots make humans' lives better. This is home to Dr. Tenma, voiced earnestly by Nicholas Cage, the genius head of the Ministry of Science, and his brilliant but mischievous son, Toby (Freddie Highmore).

But when an experiment goes horribly wrong and Toby is killed, the devastated Dr. Tenma desperately builds a robot replica of his son. Programmed with Toby's memories uploaded from a strand of the boy's hair, the robot looks just like the cocksure teenager. Soon, however, Dr. Tenma realizes his souped-up copy isn't the real thing and tells the boy to scram.

And so Toby, longing Pinocchio-style to be a real boy, embarks on a lonely search for his place in the world. Landing in the robot graveyard that now covers the Earth's surface (a visual echo of the deserted junk piles of “WALL-E”), Toby is dubbed Astro by a trio of ragamuffin revolutionary robots. His closest friend is the sassy, purple-haired Cora (voiced with entertaining sass by Kristen Bell), part of a gaggle of smart-mouthed urchins who believe he's a kid like them. Well, you know, a flying kid with headlights for eyes and machine guns hidden in his butt.

Highmore, who's played a string of major children's roles, does a fine job as the adolescent Astro. While on Earth, Astro must fight for survival (Nathan Lane stands out as the deliciously devious Ham Egg) and eventually for the future of Metro City.

“Astro Boy” introduces the big ideas that made Tezuka's work timeless, verging on profound — identity, humanity, tolerance and love — but doesn't get very far. Instead, the story is bogged down by heavy-handed political overtones, as good “blue” energy, touted by the environmentally minded Dr. Elefun (Bill Nighy) clashes with evil “red” energy, favored by the war-mongering, power-hungry General Stone (a gleeful, growling Donald Sutherland). Stone, a shoot-first, ask-questions-later kind of guy out to get Astro dismisses a political opponent as a “damn, dirty hippie,” the kind of obvious, overly broad writing found throughout the film.

That's the problem with the high-energy “Astro Boy.” The film's visuals are dazzling, with eye-popping colors, cinematic angles and edits and vertiginous action sequences that look phenomenal on a large IMA-- screen. It moves quickly, and we feel Astro's exuberance as he discovers the rockets in his boots for the first time, zooming and swooping through the clouds, his big brown eyes alight. But for the most part, the uninspired script weighs the movie down. “Zany” minor characters' attempts to inject humor into the overly literal proceedings — including a jittery robot valet patterned after “Star Wars'”C-3PO — are lame at best.

Produced by Hong Kong-based Imagi Animation Studios, Pixar this ain't.

The movie also makes sure no moral is lost on audiences, smacking viewers over the head with preachy dialogue. One sampling: “That robot had more humanity than most of us.” Phew, glad that was spelled out for me, avoiding any pesky interpretation. There's also a clumsy Christian parable thrown in for good measure.

“Astro Boy” is the newest, flashiest interpretation of the 50-something Tetsuwan Atomu, or Mighty Atom, in Japanese. The comic spawned a 1960s black and white cartoon that aired in Japan and the U.S., in addition to a live-action series, video games, and reinventions in the 1980s and 2003. Tezuka, credited with creating the big-eyed anime aesthetic, and Walt Disney were admirers' of the other's work; Tezuka was reportedly invited by Stanley Kubrick to work as an art director for “2001: A Space Odyssey.”

There's even a brief visual homage to the celebrated artist early in the film, with a cartoon scientist clad in Tezuka's signature beret and dark-framed glasses.

While this tricked-out take on the boy robot is eye candy that's sure to impress in 3-D, “Astro Boy” attempts at exhilaration remain disappointingly earthbound.