One night when searching for some inspiration on the almighty internet, I came across a simply Javascript game in which a stream of sand (or other substance of choice) fell down from the top of the screen (in color and amount of choice) to a ground which you could modify (in material of choice). I don't recall name or URL, but I did take a couple of screenshots of the game, you can see them below. It was a very relaxing timewaster, could play around with it for hours without getting tired. If you find it again, let me know.