I have a couple of times, and some of us played with Adam once--but that game was sorta atypical of the kind of game I'd want to run (since most of us played characters who didn't know anything about magic). I could post some general summary of the mythology tomorrow or something, but the general idea is that there are two (relevant) kinds of magic, and the most common kind, you get by going insane and re-forming the world to fit your particular insanity. The other kind of magic is the kind you get sort of accidentally, by fitting really well to some archetype that society has created. (Technically there's a third kind of ritual magic, which anyone can do, but most people don't know about it, and it's not generally particularly powerful--and involves LOTS of work and sacrifice, so it's not the kind of thing that would be fun to do as a PC, unless you're doing a street level game, since you can only do something once or twice.) There's a similar atmosphere as that in Mage, where there are lots of big organizations who have goals that probably hurt PCs. The mechanic is a percentile mechanic (it's really not as bad as "percentile mechanic" makes it sound), which seemed really simple and intuitive to me--in a good way, as in they didn't add extra complexities that don't buy you anything big. The sanity check sort of mechanic (through which you can go insane and get magic) is pretty cool, but I don't remember very many details right now.
Paranoia would also be cool, but hopefully Mike has time to run Saturday.
