This book is primarily dedicated to "The Harold," the standard of long-form improv. It's a difficult form to master, but one that can impress, entertain, and even touch both audience and actors profoundly on stage. There is a shortage of quick, easy games in this book. Even those that are detailed exist to help build on the Harold. This book is really meant for those who are ready to graduate to the next level of improv.
Many people don't like the Harold, but all long-form comedy improv, at some level, uses some variant of the Harold. If this isn't what you want, spend your time and money finding out more about Paul Sills' Story Theater (which is, of course, not covered in this book). Be warned, though, Story Theater often isn't funny, and appeals more to art afficianadoes than "WLiiA" fans, and isn't as renumerative.
Most of the book is given over to an explanation, not of performance standards or guidelines, but of the philosophy underlying improv in general, and the Harold in particular. If that's not what you want, go get another book. The standards in this book, moreover, are really intended for larger groups. The four-player format of "WLiiA" would be unable to keep up with a full Harold. Be sure you have enough actors ready to do the next big thing before you sink your money into this book.
This isn't a beginner's text for amateurs, it's for those who have a committment to creating improvisational art. If that's you, this is your book. If not, you're in a bad way spending money on this puppy. Know yourself and your team before you invest your earnings on this slim volume.