you move your mouse to receive the balls. Before you start this game, you will see a paper with some introductions in it. You can select your control mode, and choose the degree of difficulty with the dimension scale in the left side of the paper. A harder degree always has a higher speed. If you are ready, click ?Pong? to start. Then you will see a white board in both left and right, you can only control the right board with your mouse to go up and down. Use S to slow the speed of balls, use M to change /stop the music, a red ball with plus sign in it will raise your pad width, and a blue ball with subtraction sign in it means decrease the width. Try hard and you will get a high score.