I was at a film shoot as a PA yesterday and had a whole lot of down time. So (instead of doing my own actual work), I played Glitch. A bunch of the cast and crew would walk by me and ask "What's that? It looks very very cool."
It got me thinking about how to describe it to people. The best I've come up with is "Take Farmville and exploded it. Then mate it with EVE Online. Then get Salvador Dali to play Little Big Planet for a few hours and have him design it."
Still not quite right.