Games: Agency as Art is a book by author C. Thi Nguyen. It analyzes gaming as a mode of art and posits a theory of what games deliver to players that is unique and distinct from other media.
Theory of Fun for Game Design is a book by longtime game designer Raph Koster, who analyzes learning and design systems in gaming.
The Building Blocks of Tabletop Game Design is a book written by Isaac Shalev and Geoffrey Engelstein, aimed at game designers looking to expand their knowledge of gaming mechanisms.
Gametek is a book on tabletop gaming by author Georffrey Engelstein. It covers a wide variety of topics including the math and history underscoring games and game design.