Click the green flag to see a random moiré pattern. Click the stage to show four buttons. Click the buttons to make a pattern by changing only that specific property (direction, size, fisheye effect and whirl effect). There will still be a bit of randomness though.
It might take a couple of minutes before the real craziness begins :) Switching to full screen mode can sometimes produces a very different moiré pattern because of the different resolution. Learn about moiré patterns here: https://en.wikipedia.org/wiki/Moir%C3%A9_pattern
