No one whose age is into double digits will find much to enjoy in this gentle, innocuous, and very dull feature based on an animated PBS series. Clifford (voiced by the late John Ritter in his most soothing tones), for those of you who haven’t met him before, is an inexplicably gigantic red dog who lives in a friendly town on a bone-shaped island along with his cute-as-a-button master Emily Elizabeth (Grey DeLisle) and her parents. When he becomes convinced that his enormous appetite is eating his family out of house and home, he–along with two doggie friends, a poodle and what appears to be a yellow mongrel–paddle off to the mainland, where they plan to join a small animal circus they’ve recently encountered at home and compete along with them in a talent contest that offers as first price a lifetime’s supply of dog food. Most of the movie has to do with the three newcomers, especially Clifford, helping the act to get good enough to win and earning the jealousy of the “leading man” ferret Shackelford (Wayne Brady) in the process, but at the end there’s a pale attempt to engender some suspense when the contest organizers try to claim Clifford for their own. The danger, needless to say, never gets very serious and doesn’t last long.

There’s nothing terribly wrong with “Clifford’s Really Big Movie,” but nothing much right with it, either. The animation is of a respectable Saturday morning television standard, but no better than that. And the whole thing suffers from a lack of energy; the story just ambles along, with each attempt at a sprint quickly losing impetus. (A couple of songs added to “montage” moments don’t help, being instantly forgettable ditties.) The characters similarly lack spark. Clifford, with his apparently imperturbable disposition, is notable for little else save his size, and it’s difficult to see youngsters really warming to him; his island companions are likewise rather tedious. As for the circus animals, they’re a pretty pallid lot, too. Brady tries to make Shackelford a canny sort, like a less manic version of Wile E. Coyote (who, apart from color, he rather resembles), but the relentlessly good-natured attitude of the script defangs him; only a skateboarding pooch who spouts some dude-ish lingo has any personality at all. Still the critters are livelier than the humans, who are uniformly dreary. (And when the contest-running villains show up, why must they be stereotypical J.R. Ewing Texans–their private army composed of Stetson-wearing goons? That just takes the “size” motif way too far.)

Toddler types and parents looking to keep them occupied for 73 minutes may be satisfied with the movie, but for everyone else it’s likely to prove a really big yawn.