Tetris is a tile-matching puzzle video game originally designed and programmed by Alexey Pajitnov in the Soviet Union. It was released on June 6, 1984. Tetriminos are game pieces in geometric shapes composed of four square blocks each. A random sequence of Tetriminos fall down the playing field. The objective of the game is to manipulate these Tetriminos to create a horizontal line of ten blocks without gaps. When such a line is created, it disappears and any block above the deleted line will fall. When a certain number of lines are cleared, the game enters a new level. As the game progresses, the Tetriminos fall faster, and the game ends when the stack of Tetriminos reaches the top of the playing field and no new Tetriminos are able to enter.