The Game Production Handbook
Rapid Development (Developer Best Practices)
The Art of Game Design: A Book of Lenses, Second Edition
Game Design Workshop: A Playcentric Approach to Creating Innovative Games, Third Edition
Characteristics of Games (MIT Press)
How Games Move Us: Emotion by Design (Playful Thinking)
Theory of Fun for Game Design
User Stories Applied: For Agile Software Development (Adobe Reader) (Addison-Wesley Signature Series (Beck))
Free-to-Play: Making Money From Games You Give Away