Tetris was originally designed and programmed by Alexey Pajitnov in 1984 for the Academy of Science in Moscow. A handheld version for Game Boy, launched in 1989 made it one of the most popular games in the world.
The object of the game is to manipulate the tetrominoes- shapes of four square blocks that fall on the playing field - by moving them sideways and rotating them in 90 degree units, to create a horizontal line of blocks without gaps. When such a line is created, it disappears, and any block above the deleted line falls as well. The tetronomes fall faster as the game progresses, and the game ends when the stack of tetronimoes reaches the top of the playing field and no more tetronomes are able to enter.