This is a relatively simple story that is just sentimental, funny, and different enough to make it a little more enjoyable than the average movie.
I am more impressed by the quality of the computer 3D animation by Dreamworks Animation, which is one of the most detailed I have seen. The Croods seem to live in the land that evolution forgot. They are surrounded by a large variety of weird creatures, most of which I am sure that never existed. Nevertheless, this makes for a visually interesting movie.