Game development is quickly gaining popularity in introductory programming courses. Motivational and educational aspects of game development are hard to balance and often sacrifice principled educational goals. We are employing the notion of scalable game design as an approach to broaden participation by shifting the pedagogical focus from specific programming to more general design comprehension. Scalable game design combines the Flow psychological model, the FIT competency framework and the AgentSheets rapid game prototyping environment. The scalable aspect of our approach has allowed us to teach game design in a broad variety of contexts with students ranging from elementary school to CS graduate students, with projects ranging from simple Frogger-like to sophisticated Sims-like games, and with diverse cultures from the USA, Europe and Asia. Categories and Subject Descriptors K.3.2 Computer and Information Science Education General Terms Design, Human Factors, Languages Keywords Ga...