great game! simple and so elegant. I'd love to be able to play it on a phone, actually.
Well I think the bottom of the screen will be empty, as the game use a square space and the phone has a rectangle screen. So pressing in the area bellow the screen would let you fire in the line from your finger to the ball, like a slingshot You could also press directly inside the game area, but then your finger hide where you are aiming.