The early puzzles: place the circles with the vertical lines in the grid and they will bounce up and down within the grid. Then place the circles with the horizontal lines in the grid and make sure there are no collisions.
Here's what I'm not crazy about: some levels are impossible in that there will be a collision eventually. However, if you can place the pieces on the board strategically so that there is no collision for the first 5 seconds or so, it will be viewed as a success.
Still, this concept is fun.