Its story, about cuddly and mismatched mammals forced to raise and return a lost human baby to its own "herd," renders it a cross between Three Men and a Baby and Monsters, Inc. But it's bereft of the charisma of the former and the energy of the latter. And its look has lost the ability to dazzle. It's one more computer-generated bit of animation in which everything is intended to look real and surreal all at once; the humans, especially, look silly and slight, as though they're sketches awaiting final animation.
Yet for all that, Ice Age is not entirely unlikable -- not because it's humorous or particularly clever (its gags, such as they are, often fail to elicit more than a weary chuckle), but because it's ultimately bittersweet; it's less a comedy than an accidental domestic drama that happens to be dolled up in kiddie-merch drag. It is, in many ways, the perfect family movie: A resilient child nearly dies in the same river that claims his mother, only to find his way home again, and an embittered father (and father figure) who's lost his own wife and child has his faith (and heart) restored. The comic moments only distract from and deflect the underlying sentiment; it's as though the filmmakers felt they couldn't play it straight, so they had to bend their tale till it broke in half.
Ray Romano, all Jersey monotone, plays a mammoth named Manfred who refuses to migrate to sunnier climes with the other primitive mammals; he's a sulky beast, possessing a tragic secret he keeps to himself. While other parents and kids head away from the snow, Manfred sloshes toward a certain doom.
Along the way, Manny picks up unwanted company: Sid, a gibbergabbering sloth voiced by John Leguizamo like an outtake from one of his one-man shows; and Diego (Denis Leary), a saber-toothed tiger seeking the baby's blood as revenge. Diego poses more of a threat than the encroaching snowstorm: He's doing the bidding of his fellow saber-tooths, who want the baby and the mammoth as fresh meat. Diego will either betray his newfound partners or discover, at the last moment, a conscience. The scenes in which these three unlikely partners raise their new child work best; they display a rare, welcome tenderness.
Where Pixar's offerings dazzle without overdoing it, Ice Age goes the opposite direction: Its look is almost boring. So, too, is much of its story. If only it didn't feel the need to keep us laughing, it might have kept on moving.