It may lack the rapid-fire whimsy of Toy Story's dialogue, but it tells a more nuanced and imaginative story than Toy Story 2, with fewer softball cultural references. As in Iron Giant and The Incredibles, Brad Bird grounds the characters with largely believable dialogue, and goes through amazing pains to legitimize its many narrative conceits. It's drop-dead gorgeous, almost the equal of Finding Nemo, with more elaborately choreographed action.
The vibrant visuals come early, from the gorgeous countrysides outside Remy's colony to the perfectly rendered ripples of water in a nearby stream. Bird isn't content with stimulating stills, however; he constantly plays with perspective and momentum. Cameras hurtle through cracks and crevices and skid to a stop, double-take and double-back, circle in ecstasy, then stop on a dime in shock. Remy's scurrying takes on a Rube Goldberg quality, as Bird weaves madly through his computerized sets and actors to get this tiny creature from Point A to Point Z. The high point is a startling sequence that begins in an alley and ends with a panoramic rooftop view of the nighttime Paris skyline. (If only Disney's Tarzan were as coherent in applying its Deep Cavnas technology.)
Brad Bird is not obsessed with gimmickry, however; his technique emphasizes character and emotion. He doesn't skimp on character animation, either. The facial expressions are phenomenal in nearly every scene. Watch Remy's eyes and head bobs as he wryly concocts his first culinary masterpiece in the kitchen, or when he attempts to communicate with his human liason, Linguini.
We are in Iron Giant and E.T. territory here: Remy can understand human speech, but his squeaks aren't understood by humans. Oh, but this isn't a film about a rat chef squeaking recipes to a human conduit. This is about a rat chef taking complete control of a human's life. Linguini is the restaurant's garbage boy, can't cook for squat, and receives the praise for a dish that was garnished by Remy. Explanations surely could never suffice, so Linguini needs a way to get this improbable rodent to cook for him. Bird's conceit is beyond charming: If you tug on a human's head hair, you can pilot them like a robot.
From there, Ratatouille becomes a shaggy underdog/rat tale with romance, courtesy of the story's lone female character: a saucy tomato named Colette, whose mentoring of Linguini simmers into a warmer relationship.