I found this a refreshing change from the usual chess problem or instructional book. Here you can play through the book and score yourself to see how well you do. Then you go back through them again to see how you can improve with better understanding. It's also good for returning to after a good time has passed, and see if you do better or worse.

The difficulty levels are randomized so you will find problems of varying difficulties throughout the book. I think this is good as you don't know what will be coming on the next move until you get there. If someone wants to do them in order of difficulty, it could be done simply by going through and doing all the ones first, then the twos, etc. Also while it might not be most helpful to one's own game to experience only what occurs at those critical moments, one can practice through how Fischer actually developed the opportunities for these outrageous moves by checking the entire games out in the back of the book.

While the other more standard problem and instructional books remain important, I wish more like this one were published.