As I watched this movie, I couldn't help but think it must have been taken from the Disney Channel. Look at all the Disney standards: taken straight from, and in order to promote, their theme park division; hero feels out of place and quests for self-fulfillment; and random musical numbers totally out-of-place with the film (unlike animated musicals, the music in this movie is, in many cases, supposed to be spontaneously created from whatever's around, but is really overdone; it's hard to willfully suspend that much disbelief.).
One GOOD thing about the movie is that most of the cast is well-known (household names like Walken and Osment join veteran voice talents Huss and Root, alongside the familiar faces of Mitchell and Bader); yet even such a strong cast (which also features Brad Garrett from Everybody Loves Raymond) can't rescue a script (and premise) that was doomed from the start. The cops and mom are stereotypes, the dad is an exaggeration, and Dex, who SHOULD be the sanest family member, can't help but fall into Disney's "everyone loves everyone" mode despite his efforts not to. While most of this is allowable to some extent in a movie aimed to kids... this is excessive. I watched it with a group of kids, and most were bored. Seems to me that to really enjoy this movie, one must combine a child's tolerance for saccharine moments with an adult's attention span. Otherwise, it's a below-average movie propped up by strong acting talent and slick animatronics.