The Amber Spyglass is the last book in Pullman's Dark Materials series. If you read The Golden Compass and The Subtle Knife you should read this book. The story is still too sophisticated for children, but it does provide a conclusion to the series, although not in a particularly satisfying way.
Some authors write crisp clean prose that keeps the reader's attention. Patterson is a master at this. In this book, Pullman never said anything in one sentence that he couldn't stretch to a paragraph or more. I really wanted to find out what happened to Lyra, Will, and the worlds of this series, but this novel really began to drag toward the end.
A movie might be the best medium for this novel. Hollywood would throw away the wasted words. Probably along with a lot of important ones. They definitely changed the whole tone of The Golden Compass when they made it into a film. Recommended — only if you read the other books in the series.