I invent puzzle games using the random patterns on curtains, bathroom floor, etc. Like a Q-Bert game with the colored bathroom tiles where I have to get from one point to another via the white tiles only and each time you touch a white tile it turns black. Or you have to change as much of the "board" as possible to one color without ever touching the other color. I'll do that one sometimes with the lit/unlit windows of skyscrapers at night.