It also looks like it’s at least somewhat related to the idea of the Lexicon game, though it seems to incorporate time perhaps a bit more structurally. (It also appears that 20×20 Room is no more. This means that the canonical link to Neel’s original outline of the idea (Neel Krishnaswami’s “Lexicon: an RPG”) is gone. However, there’s a mirror of it here.)
I’m curious to find out more about it. I find that reviews don’t explain how it works as completely as I’d like, though there is a whole series here, so maybe I’ll get it better when I read through the whole set.