"Underdog," the live-action Disney film based on the Saturday morning cartoon series that ran from 1964-73, has a tail-wagging sense of wit and fun but gets undone by an increasingly lame story and physical gags in the latter phases of the movie. Still, the movie isn't nearly as bad as you would expect when the studio holds its only press screening the night before a national opening. The film kids superhero movies even as it opens the way for clever canine jokes that do make the movie something of an underdog.

The movie's hero is a lovable Beagle nicknamed Shoeshine that cop-turned-security guard Dan (a subdued and genuinely likable Jim Belushi) finds on a street one fateful night in Capitol City. He and his son Jack (Alex Neuberger) are involved in a real-life challenge of coping with the death of the wife and mother, which gives this cartoonish comedy emotional heft.

Unbeknownst to either male, Shoeshine has been accidentally transformed into a canine crime-fighter in the lab of one Dr. Simon Barsinister (Peter Dinklage in a peerless bit of comic clowning), a mad scientist who, as he says, prefers the term "visionary." The dog can blast through walls, lift impossibly heavy objects, think faster than a human and, yes, he can talk. (Voice supplied with a down-home sensibility by Jason Lee.)

It takes a while for Shoeshine and Jack to get comfortable with these brilliant pet tricks, which makes for much of the fun in the early going. So while Shoeshine and Jack get their superhero act going -- which includes pinpointing the right costume after several false starts -- Dr. Simon, his face hideously rearranged by an industrial accident to look truly diabolical, and his wonderfully dense yet resourceful henchman Cal (a narcissistic Patrick Warburton) find new ways to do evil badly.

So the movie, under the direction of Frederik Du Chau (who directed that other critter comedy "Racing Stripes"), seems to have many things going for it as a family comedy. Alas, it fritters this all away with a "Batman"-style plot to destroy Capitol City by Dr. Simon and a gang of bad dogs led by a tough called Riff Raff ("Everybody Loves Raymond's" Brad Garrett).

The script by Adam Rifkin, Joe Piscatella & Craig A. Williams doesn't so much go to the dogs as rely too heavily on dogs doing things cute or amazing to take audience minds off a stalled story.

The pet tricks are quite good, and the animation of the animal mouths and the actors' voices synch well. This includes Amy Adams as Shoeshine's love interest, a saucy Spaniel named Polly. Other effects are just so-so, and the production design reflects the film's divided sensibility: Some sets and locations have true grit while others feel like backlot fakery.

Buena Vista Pictures
Walt Disney Pictures presents in association with Spyglass Entertainment a Barber-Birnbaum/Jay Polstein production in association with Classic Media
Director: Frederik Du Chau
Screenwriters: Adam Rifkin, Joe Piscatella, Craig A. Williams
Story by: Joe Piscatella, Craig A. Williams, Adam Rifkin
Producers: Gary Barber, Roger Birnbaum, Jay Polstein
Executive producers: Eric Ellenbogen, Bob Higgins, Todd Arnow
Director of photography: David Eggby
Production designer: Garreth Stover
Music: Randy Edelman
Co-producers: Erin Stam, Rebekah Rudd
Costume designer: Gary Jones
Editor: Tom Finan
Voice of Underdog: Jason Lee
Dr. Simon Barsinister: Peter Dinklage
Dan Unger: Jim Belushi
Cad: Patrick Warburton
Jack: Alex Neuberger
Molly: Taylor Momsen
Mayor: John Slattery;
Voice of Polly: Amy Adams
Voice of Riff Raff: Brad Garrett
Running time -- 84 minutes
MPAA rating: PG