Reddit reviews The Aesthetic of Play (The MIT Press)

The Aesthetic of Play:

Play takes place in the mind of the player. The book offers heuristics for analyzing the playfulness of a game. This allows you to create intrinsically engaging games – playful games.

Advanced Game Design: A Systems Approach:

Games are essentially systems – parts that interact with each other in complex ways that generate interesting gameplay. You will learn to observe systems, and start to see them everywhere. You will also learn to create them, harnessing complexity and emergence.

Thinkertoys: A Handbook of Creative-Thinking Techniques:

Not a game design book, but it greatly improved my ability to think creatively, come up with non-obvious solutions, and alter my daily life mindset towards ordinary things. Which is relevant to designing games.