Just want to add a +1 for these, particularly Art of Game Design, A Theory of Fun, and the Tanya Short/Tarn Adams books.

To add to your list: I have a copy of Designing Games: A Guide to Engineering Experiences that I recently started reading.

Also want to add +1 for A Theory of Fun by Raph Koster. It's a very lightweight read with pictures, yet still changed the way I think about what is fun, and learning in general.

I enjoyed this book to practice game design:

Challenges for Games Designers: Non-Digital Exercises for Video Game Designers - Brenda Romero / Ian Schreiber

Another good one on the game design side of things:

Designing Games: A Guide to Engineering Experiences by Tynan Sylvester (RimWorld)

Ha! I must have been editing my comment as you were writing yours. I just started into Sylvester's book.

+1 for A Theory of Fun

Raph illuminated things about the psychology of what makes games fun that Id never realized nor seen before.