My oldest son was excited to see it, and wanted to wait until we could all go even though he could have gone earlier in the week since school is out. Frankly, I was happy to go to the movies since I can't really remember what the last thing I saw in the theater was. (Cars? Monster House? Well, I know I've seen at least a few movies in the theater since we've had kids.)
We were initally nervous because the reviews that we read gave the movie poor scores and complained a bit about that there were too many characters to follow. We were also prepped for the reviewers to dislike the movie by the fact that our oldest was reading the book that this moive was made from at school, and the teacher handed him a worksheet to fill out about the differences between the book and the movie. Clearly, the book had been changed a little to accomodate a screenplay. I always expect that to happen because of the intrinsic differences between books and movies. Usually, since changes have to be made, and they weren't the ones that the reviewer would have made, there's going to be several reviewers handing out bad scores purely because of a lack of objectivity. As far as the too many characters part, I didn't think that there were any more characters to follow than some ensemble comedies. Granted, those are for adults, but since my oldest son didn't have any problem with all of the characters then I have to assume that the reviewer needed something simpler to watch, like Waiting for Godot or perhaps some off-Broadway one person show.
I enjoyed the film for what it was and was not encumbered by having to compare it to the book.
On the other hand, we watched the Speed Racer movie after dinner - and I have no idea what someone unfamiliar with the source material would think of the movie. It was very much like watching a video game during most of the action sequences and jumped into flashback quite frequently in the first part of the film. I'm thinking that someone that never saw the original cartoon has no clear idea what is happening until about 30 minutes in, and it's still dodgy at that point.
Now I'm going to go shoot zombies parasite-infested villagers zombies.