It is your responsibility to control two shapes, which you may change by touching the screen's boundaries or by using the mouse's arrow and left and right keys. Ideally, you should change them such that they take on the same shape as the incoming objects that show at the top of the screen. You will get points if your matches are correct and you proceed through the game. If, on the other hand, you are unable to match the appropriate forms, you will lose.
How to play
How To Play Matching Shapes