I had a lot of trouble deciding if this book is worth my money, especially considering the standard cost of: $75. There are almost no reviews about this book on the internet, which was why the decision was difficult.
I ended up getting this book for $30, and I still somewhat feel ripped off. This book does have some value related to game concept and design, as well as a few interesting concepts, BUT, compared to other books with a lower price, this book isn't very good.
Because of this book, I learned the basics of what a game engine is, which is a new concept to me. I also learned a few interesting concepts of game design, but the book jumps from topic to topic. Reading the code, it seems that this book assumes you are advanced, but reading over the paragraphs, it teaches you introductory concepts such as variable initialization and arrays AFTER it was implemented in code.
This book is very confusing for beginners, and not much use to intermediate programmers, and completely useless for advanced programmers. It doesn't exactly explain what a game engine is, and how to use it properly. It doesn't explain any of the methods that the game engine contains... It just uses them...which isn't good for a beginner.
I still think that for other intermediate programmers, this book has some use by teaching you about game engine and code structure, which I haven't found yet in a book. If you are looking for a game programming book to read after introductory java books, i suggest you look into
Developing Games in Java (which is slightly difficult, but if you spend enough time on it, any beginner could understand it)
or Killer Game Programming in Java. (this is more advanced than the above).