“The Secret of Nimh” contains that absolute rarity among feature-length animated cartoons, an interesting premise. It is: What if a group of laboratory animals were injected with an experimental drug that made them as intelligent as humans? There have been smart animals in the movies for years, of course, but they were always playing quasi-humans in a universe where the real humans were seen mostly from the knees down. Now here’s a story that concerns itself with the problem of being a rat and having a superior intelligence.

Although the idea was what intrigued me about “The Secret of Nimh”, the movie itself represents a philosophical statement for its makers. The animators who made this film were previously employed at the Walt Disney Studios, where they were heralded as the “new breed,” groomed to replace the veterans who started with Walt himself and were all past retirement age. But halfway through production of the Disney animated feature, “The Fox and the Hound”, a group of new breeders walked out and, led by director Don Bluth, set up their own shop at MGM.

Their complaint was that Disney was cutting corners on painstaking traditional animating methods. Their vow was to make a non-Disney movie in the old Disney tradition. The main difference between traditional Disney animation and cheaper, newer methods is in the areas of body movements and backgrounds. Bluth and his followers wanted to make a movie in which the characters would have lots of body language (not just moving lips and rolling eyes), and in which the backgrounds would be detailed and interesting, not just repetitive roll-bys. In “The Secret of Nimh”, they have succeeded in reproducing the marvelous detail and depth of the Disney classics. This is a good-looking, interesting movie that creates a little rodent world right under the noses of the indifferent local humans. The story is perhaps a little complicated at first, especially for younger viewers, but a flashback helps make things clear, and then the adventure begins.

Making his fourth directorial feature after contributing to the screenplays of “The Bourne Ultimatum” and “Ocean’s Twelve,” among others, Nolfi maximizes medium-scale resources to give “Elevation” a fairly expansive feel. Cinematographer Shelly Johnson takes full widescreen advantage of the magnificent Colorado scenery, while visual effects supervisor Nathan McGuinness’ nasty four-legged nemeses are seen enough to satisfy, albeit mostly held in eye-blink reserve by editor Joel Viertel. H. Scott Salinas’ big orchestral score also helps pump up a movie whose global-crisis premise is somewhat belied by the relative modesty of onscreen spectacle.