A game where(usually) involves things like sand, oil, water, and such falling from the top of the screen, in some versions, you can stop it from falling, and make various other things appear, like walls, a little rotating thing, and fire. The game often has very realistic physics, and can be entertaining. No one really knows where it originated, and many similar games are around, like "powder game", one without falling things, and MANY different objects, such as ant, magma, virus, fan, and bubble, and little men called "fighter". some of which are in "falling sand".(there are many versions of this game, most being in Japanese.)
I was playing that falling sand game, and made some burning oil, then I clicked this weirdly named thing, and a ball started rolling around.