It took the creative giants behind Men in Black II five years to come up with a disappointingly uninspired sequel that not only treads familiar ground but does so with far less pizzazz than the original. It took the forces behind Stuart Little 2 a mere two years to unveil their imaginative and engaging follow-up, which revolves around a fresh story line that presents its stars with new challenges, obstacles and emotional opportunities. Like Lilo & Stitch, Stuart Little 2 has some valuable life lessons for youngsters experiencing many of the same kinds of growing pains as the characters.

The new film finds Stuart (the voice of Michael J. Fox and an outstanding team of digital artists at Sony Pictures Imageworks) happily ensconced as a member of the Little household, which, in addition to Mom (Geena Davis), Dad (Hugh Laurie), George (Jonathan Lipnicki) and Snowbell the cat (voiced by Nathan Lane), now includes a baby sister. But George has his own friends, and Mom is overprotective. So Stuart longs for a friend who's... well, his own size. His wish is granted when an injured bird suddenly tumbles into the passenger seat next to him as he's driving home from school one day. Margalo (voiced by Melanie Griffith) is on the run from the Falcon (voiced by James Woods). The Littles welcome her into their home, and Stuart experiences his first crush. But the independent Margalo is not all she seems, and one day she disappears. The film's funniest sequences have Stuart and Snowbell venturing out into the world to look for her.

Even if Stuart Little 2 lacked other attributes, the digital artistry alone would make it worth the price of admission. There's no question that state-of-the-art computer-animation technology has raised anthropomorphism to a whole new level, and while no film may ever match the disarming charm and emotional appeal of the first Babe -- or Donkey's sheer exuberance of personality in last year's Shrek -- Stuart Little 2 does a masterful job of combining digital imagery and voice performance to create totally believable animal characters. It's not so much that Stuart looks or acts like a real mouse as that he is a believable character whose expressive face communicates totally identifiable human emotions. Snowbell, of course, is a real cat (actually five Chinchilla Persians were employed, each one specializing in a particular task) but without the seamless animatronic work and Lane's purrfect voice inflections, he could have ended up as hokey as the felines in the dismal Cats & Dogs.

Stuart and Snowbell present the perfect marriage of digital artistry, animatronic advances, voice performance and, in the case of Snowbell, animal training. Falcon comes across as more of a traditional cartoon figure, but what he lacks in facial expression is more than made up for by Woods's menacing voice. And in her first stab at voice acting, Griffith scores big-time. Without her subtly shaded intonation -- her Margalo manages to sound innocent, friendly, down-to-earth and sultry all at the same time -- the little bird would not have been half as successful. Monty, an alley cat introduced in the first film, makes only a brief appearance but nearly steals the whole picture with his ingenuous one-word plea to Snowbell: "Please...," uttered in the inimitable style of Steve Zahn.

The human actors don't fare nearly as well as their furry and winged co-stars, partially because they're saddled with more one-dimensional roles. While Lipnicki brings a believable kid-ness to his part and Laurie gives Mr. Little an eccentric sweetness, Geena Davis is almost like a Stepford mom, so smiley and loving she seems programmed. Children, the natural audience for this movie, probably won't even notice.

But this film isn't just for kids. There are enough adult-friendly ideas and humorous lines of dialogue that parents -- and other grown-ups partial to family fare -- will be entertained. Rob Minkoff, picking up the directing reins for a second Stuart go-round (in addition to the original mouse movie, he also directed Disney's megahit The Lion King), keeps the story moving briskly without it ever feeling hurried. He rejects the urge to be cutesy and avoids even a whiff of cloying sentimentality.

No, the film is not perfect, but parents and kids have a lot of movies to choose from this summer, and the difference in character and story quality between Stuart Little 2 and something like MIIB is astounding. MIIB may be skewed more toward adolescent boys while Stuart Little 2 targets a younger audience, but it's difficult not to mention the two together. Both are sequels to justifiably successful earlier films, both kept their original directors, and both are opening within two weeks of each other -- but only one is worth seeing.