Unike its titular child android, "Astro Boy"'s oh-so earnest zing is somewhat attenuated by the lack of a definitive soul to make it stand out. Which isn't to say that David Bowers' 3-D animated sci-fi is a screwed-up experience -- thanks largely to its amusing one-liners and side characters -- but its theme of a boy trying to fit in among those who are different from him fail to stand up to the likes of, say, "Pinocchio," and "Iron Giant." <br /><br />In the lustrously hi-tech Metro, a city floating above piles and piles of metal scraps, humans are served by robots that are guided by the late Isaac Asimov's robotic laws. Metro resident Toby (voiced by Freddie Highmore) is seeking to follow in the footsteps of his father, Dr. Tenma (Nicolas Cage), who created most of the city's machines. However, an accident that leads to Toby's death prompts the sorrowing dad to create a robot in Toby's image in a bid to replace his son. Astro, as the mechanical Toby eventually becomes known, is shattered after Dr. Tenma rejects him for not being able to live up to his human counterpart, and realizing that he's not who he thinks he is, Astro leaves the Metro in search of a place where he feels he'll belong.<br /><br />Bowers' cinematic translation of a 1951 manga by Osamu Tezuka is an uneven -- albeit beaming -- trip, typified by the likes of Cage and Bill Nighy who sound bored, even if Donald Sutherland and Kristen Bell feel game for their roles. But it succeeds in creating an allegory on the rift between different classes, even if they are frustratingly glossed over in service of a predictable story and a few humdrum action. Despite its shortcomings, "Astro Boy" still proves humorously compelling when its hero spreads kindness courtesy of his cant-do-bad heart.