Not a game, just a little homebrew app that lets you draw 2D shapes on the screen, which then obey the laws of physics – or gravity, at least. It’s fun to play about with, but slightly hampered by a small drawing area and big crayonish lines. (At least, if you’re as hamfisted as me it is. The screnshots and videos online show an accuracy that’s beyond me.)
Still, if you can use this sort of thing, I heartily recommend giving it a download.