I read the Swift Apprentice and most of the 2D Games. Fantastic Books!
I would like you to consider create a GameplayKit by Tutorials Book.
Its really a shame the almost none existent documentation on how to implement the GameplayKit API.
I only found a couple here on your website and one video in youtube.
Covering all the topics a not only Entities and State Machines but also Rule Systems, Desicion Trees and integration with Xcode (shown in the WWDC 2016 but not taught enough)
I’m agree with hcastellanos22. In the first version of the book you introduce GameplayKit. This is a fantastic tool you must retake in a tutorial’s book. I am trying to use it in my new games, but it is always good to have new tutorials from you.
+1 for this as well. I’ve read the 2D and 3D game by tutorial books and wish there was more content and examples. I like learning about game development and those books were great, hope to see more.