This book is a good introduction to the Godot game engine by creating 5 different mini-games, which can be expanded as much and as far as the reader wants to, touching several common aspects of 2D and 3D games - animations, synchronization, scripting, basic physics, dynamic instantiation, signals, global variables, state machines, shaders, and exporting the game to other platforms.
That said, it's quite a small, easy to read book and it definitely serves as an entrance door to tackle other common game development topics (asset workflow, pathing, AI, debugging, performance optimization, to name a few) - getting the reader more excited to pursue more on their own.
Finally, it's important to say that, just like any other ever-evolving platform, Godot has some bugs here and there so using it require some flexibility from the reader (eventually changing the initial version of the editor used) - I used 4.2 (stable) and had no problems