Yes I think it could be a good game on phone too. So I am working on an Android version now. I could also just make a touch screen binding on the html5 web version.
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.