Zottris is a single player, shareware, falling block game. Square blocks fall from the top of the screen to the bottom. When they hit the bottom of the screen the player can destroy them but they cannot be destroyed in flight. Destroying blocks costs the player Zot points which can only be replenished by generating a row of the same colour bricks which disappear and score the player points. As the player's point total increases they advance to another level, the gameplay remains the same but the background colour changes and the blocks appear and fall at a faster rate. The game ends when the bricks reach the top of the screen. The game has optional sound but has no save/load or high score functions.