I liked the movie, and so did my 2.5 year old son. It was his first movie and managed to hold his attention for the entire time. He's been talking about it ever since. A caveat though, we're both Clifford fans to begin with.
The movie is near perfect for its target audience of preschoolers. There are no scary parts, the story is linear and clear, there's no violence, and it has a happy ending. The plot lacks the complexity of many other of the animated movies marketed toward older children. It is straightforward story with little development of the character's motivation except for a few key things important to the story. The main characters are consistent and entertaining, and the Big Red Dog is well presented in proportion to the rest of the normal sized world. Some of the most comical sequences are when those unfamiliar with Clifford see him for the first time. Kids seem to love the idea of a HUGE friendly dog, and it's played up to good effect in the film.
The basic story is classic Clifford. He means well and is trying to do the right thing, but his efforts don't always work out as planned. Except for Clifford's family and friends, not everybody understands that Clifford's heart is as big as the rest of him. Clifford's size is as much a hinderance as an asset, but in the end people love him because he's a great dog, and not just big.
For those that that have seen the TV show and/or videos, the movie plays like an extended episode of the show. Same characters (Many of the minor ones don't get a part in the movie), mostly the same voices, and the same look and feel, though the animation is of a higher quality than on the show. There's even some attempt at 3-D animation going on, although the backgrounds are for the most part flat. The soundtrack is better than the show too :). Characters are consistent from the movie to the show, and a several of the running gags from the show are incorporated into the movie.
Whoever made this movie took the best of the show and successfully turned it into a feature length film.
The movie is dedicated to John Ritter, and I believe it is the last film he did.
