Picture yourself playing Super Mario Brothers. Bring to mind the sensation of steering Mario around, the feel of jumping over pipes and platforms. What is that feeling? Where does it come from? Why has no one talked about it before? How would you go about creating a sensation like that? In digital game design, "feel" is the single most overlooked facet of game design: a powerful, gripping, tactile sensation that exists somewhere in the space between player and game. It is a kind of "virtual s...