The book does have several shortcomings which prevent it from being a great book, the most important of which is that the content is fairly limited. It's less than 300 pages, and a significant amount of space (especially in the later chapters) is taken by source code listings. Of course, this is somewhat offset by the book's relatively low price.
If you buy this expecting it to be the ultimate guide to physics in games, you'll be disappointed. However, if you buy it as an introduction to physics in games (which how it's intended to be used), I think you'll be happy with it.
As an example, the simple trajectory problem, launch a particle in constant acceleration with no friction, is presented here as four separate problems; launch a particle with target at same height, launch a particle with target higher, launch a particle with target lower and launch a particle horizontally with target lower. No physicist would approach the problem this way, it is absolutely trivial to present them all as the same problem with the same general solution.
Occasionally the book lapses with just outright errors. The most serious so far I've seen is the cylinder rolling down a plane without slipping is solved by assuming the frictional force is the static coefficient of friction times the normal force. In fact, the force can be any amount less then this. As a result the solution given has the funny property that it will roll up the plane for small angles.
The book isn't all bad, and may well serve it's primary purpose, which I assume, is to give a litany of examples that game developers may paste into their games. It certainly has lots of examples, and most are correct physics, still, perhaps with my bias as a physics professor, I was hoping for a bit more physical insight into the problems.
The overall mathematical level is 'easy'.
David does not dig deeper into mechanics than it is necessary for a game.
The book is usefull for a beginner but also deserves the 'knowing' as a good cookbook for the games-level.