Set during the Ice Age, the real story involves three very different animals--a rascally sloth (voiced by John Leguizamo), a droll woolly mammoth (Ray Romano), and a sharp-edged sabertooth tiger (Denis Leary)--forming an unlikely friendship as they set out on a journey to reunite a lost human baby with his parents.

"Ice Age," directed by Chris Wedge, is slight and harmless, but little else. Running just 75 minutes, the screenplay (by Michael Berg, Michael J. Wilson and Peter Ackerman) seems almost dull and old-fashioned when compared to the more clever, more original "Shrek" and "Monsters, Inc." The dialogue has a few sparsely funny zingers, but the writing is mostly unsophisticated and underdeveloped. Even the recent "Jimmy Neutron: Boy Genius" was wittier.

The three characters--Sid the Sloth, Manfred the Mammoth, and Diego the Tiger--progressively get more endearing as the film progresses, but they are no match for the scene-stealing Scrat. It is greatly dissatisfying that, regardless of the misleading trailers, Scrat is barely on view. Director Chris Wedge hilariously voices the sounds Scrat makes; hopefully he will one day get his own movie.

Like the unimpressive storyline, "Ice Age" boasts fine computer-generated animation, but it is a step down from the ingeniousness of the "Toy Story" series, the sheer audacity of "Monsters, Inc.," and the lifelike movements of the characters in "Shrek." When humans are seen in "Ice Age," they look passable, but move with less smoothness than has become accustomed.

In the annals of big-budget, modern-day animated excursions, "Ice Age" is one of the lesser attempts. Aside from the appearances of Scrat and a few touching character moments between Manfred, Sid, and Diego, the film comes and goes with the blink of an eye without much to think about on the way out. As a movie for children, it will undoubtedly delight, but the adults in the audience will find themselves with less than they expect to be entertained with.