Figured I'd leave some general instruction/hints here:
There are 3 orbs on the screen. You must shoot one of the orbs in-between the other two orbs in order to complete your turn. If you fail to do so your opponent (the computer) is awarded a point. If you succeed then your opponent must do the take it's turn. You cannot shoot the last orb that was shot by your opponent. The orb must make it a little way past the center of the other two.
The goal of the game is to make the perfect shot so your opponent cannot shoot an orb in between the other two.
If you are near a wall sometimes you can do bounce shots. If the two orbs that you need to shoot in-between are near a wall sometimes you can shoot your orb at the wall between the two and have it come back out and it will count.