http://itunes.apple.com/us/app/dropzap/id338490375?mt=8
The sequel, DropZap 2, will have two shapes. Circles will behave as the squares do in DropZap. But it will also have squares, which also fire lasers and shrink, but they do not allow lasers to go through them. For example, when fired upon from the right, a square will not allow the laser to continue beyond it to its left.