Something kids can really laugh at
I was reluctant to buy this considering I didn't know anything about the comics, and it struck me as juvenile and sort of predictable. BUT, I gave it a chance and it turns out that it's really good - if your goal is to give your kids something they can genuinely laugh at. Adults can enjoy it too, but I think kids can enjoy it more.
It's basically a friendship story, with scenes that emphasize the importance of friendship, sticking together, and perseverance.
It's filled with goofy, good-natured fun. Gross ideas are played for laughs throughout the film, but that's sort of the point.
Valuation of creativity, imagination, and art is shown throughout the film. If you have a kid who likes to draw, this might inspire them to make their own comic - who knows?
The antagonists are characters with no sense of humor, while the protagonists are kids who love to laugh. There is a message here to not take life super-seriously, and that a lighthearted outlook is best.
The only content I found questionable was a scene where Harrold (in an attempt to explain how mean Krupp is) makes a sketch of Krupp roasting a cat with a flamethrower. This is forgivable only because the drawing is covered with a "censored" label, and when George asks "Did that really happen?!" Harrold admits "Technically, no. But it may as well have!" I'm not so keen on introducing ideas about violence toward animals to young kids. Granted it's used to vilify, and recognized as a terrible act. Also, there is a comment about "jars of plucked out eyeballs" made by one of the boys speculating what they might find inside Krupp's house. Again, this is not imagery that young kids should be given. But maybe I'm just sensitive because I have a vivid imagination.
All in all, the film is pretty innocent, and probably less dark/violent than your average Disney film.
Whether you like this movie or not will depend on your sense of humor. I appreciate it for the fact that it's easy for kids to laugh at because the humor is simple and goofy. Too many kids movies these days are filled with jokes kids don't get - that are more enjoyable for the parents than the kids. This movie isn't so. It's really for the kids first, and hopefully the parents can laugh along too. My 4 and 1/2 year old laughed lots during this movie. I think it's best to show this to your kids while they're still easily amused by goofy, simple humor, mostly centered around bodily functions and undergarments. There will be plenty of time to "grow up" later. :-)