A very cute, very enjoyable fantasy fairy tale. There really isn’t a lot more to it than that: it’s simple, plain, well-written escapist fun. Like all of Gaiman’s work that I’ve read (which is nearly all of it) it’s very well written, and hell of a lot of fun. Highly recommended.
I was inspired to read this by the movie. It’s very similar, the movie was generally pretty faithful. Most of the plot changes were pretty minor: just to streamline and shorten things, largely. The movie expanded the minor characters; they became bigger, more memorable roles. This was probably to attract the big names they got, but wasn’t actually a bad thing. Gaiman was very clearly attempting to create a rich supporting cast.
The movie did make one very substantial change. And, with the benefit of reading the book, it was very clearly for the worse; and quite forced. I won’t say what that was, except to say the book is better without and the movie would have been equally so.