The game requires you hit the ball into the goal, therefore the angle of your player and the ball has to be considered. Even from a distance you can quite easily score, as mentioned the game is similar to Air Hockey where you can use the walls to bounce the ball off, so even if you cannot score in a straight line if you know your angles there will be a chance to hit it off the wall or opposition player. You can use the practice offline option on the top right corner of the screen in order to help you get used to the games shooting mechanics.