The two sides of the screen scroll in different ways. On the left side, you must keep the ball from going off the top of the screen and on the right side, you must keep the ball from being squashed at the bottom. Use A and D to control the left ball and right and left arrows to control the right ball.
You can play this with a friend but its meant to be played by one person.
Yes, this game does get harder the farther you go into it.
M to mute.
Q,W,E,R to change music or stop/start music