Oh, how to play,
The top boxes with lines are your angle selector. Click it once then click on the screen to place it.
Once placed, you can drop and drag. to destroy the line, drag it to the top of the screen
The goal is to get the pink ball to hit all the green boxes and then hit the exit door at the bottom with using the least angled lines as possible.
The on off switch changes the angled lines to become bouncy or not.