Different objects are falling down from the top of the screen. There are seven different blocks, formed like letters
I, J, L, O, S, T and Z. Each object consists of four squares. Using the arrows on the keyboard, the player can rotate the objects by 45 degrees and move them left or right. The goal is to complete as many horizontal rows as possible. Completed rows disappear from the screen. As soon as the screen is filled with objects up to the top, the player looses.