In addition to being the infamous delusional cry of the title character, "The sky is falling" was also what some critics thought was happening at Disney, which would explain Chicken Little. But their grumpiness is unwarranted and a little puzzling. There's nothing in this film to suggest an apocalyptic end to the successful formula Disney has used for decades -- in fact, other than a crisp switch to digital animation, Chicken Little is Disney at its most Disney-like. The film fits right in to Disney's tradition of selecting fairy tales and children's stories that are just ripe for revitalization, yet Chicken Little has a space-age feel as well -- literally, as the plummeting heavens are actually the byproduct of an alien invasion. Not only is this a clever idea, but it opens some terrific visual possibilities for robot gizmos, which the animators eagerly bring to the screen. But Disney is still low-tech in its agenda, as the crux of the conflict involves the poultry pipsqueak trying to prove himself to his widowed father. Zach Braff and Garry Marshall make both halves of this relationship work with labor-of-love performances. The world they inhabit is colorful and speckled with different species, and it really has the feel of coming from a storybook -- like if you got to city limits, the drawing might just end. One welcome change is that Disney -- usually so safe on the sidekick front -- deviates from the familiar with two risky choices: a truly ugly duckling named Abby Mallard (voiced by Joan Cusack), and a not-so-runty Runt of the Litter (voiced by Steve Zahn), each of whom takes a little warming up to. That might be the most legitimate complaint leveled at Chicken Little: the whole thing takes a little warming up to. But once it starts to take off, it's pretty darn agreeable.