Galloway's Gaming: Essays on Algorithmic Culture

Short but sweet. A good, clear discussion of the concept of diagetic play. Galloway says of video games, "One must interpret material action instead of keeping to the relatively safe haven of textual analysis."

I agree. In my book I came at this issue through activity theory, a very different approach, but, for the most part, the same sensibility as Galloway's, that video games are living actions.