Tetris (Russian Cyrillic: Тетрис) is a puzzle video game available on a wide range of platforms, most famously on the original Nintendo Game Boy. It was created in 1985 by Russian programmer Alexey Pajitnov while working at the Computer Center of the Russian (then Soviet) Academy of Sciences. He was assisted by fellow programmer Dmitry Pavlovsky and high school student Vadim Gerasimov.
In its most basic form, gameplay consists of a small contained area that fills up with random falling tetrads – blocks consisting of four squares in varying configurations. The player can move the blocks horizontally, rotate them 90 degrees, or speed up their descent. The object of the game is to earn points by forming wall-to-wall lines across the bottom of the play area, causing them to be destroyed. More points are awarded depending on how many lines are destroyed at once. When the number of lines destroyed crosses a certain threshold, the rate at which the blocks fall increases, and the player moves on to the next level. If the blocks accumulate beyond the top of the screen, the game ends.
The Russian folk song "Korobeiniki" ("Коробе́йники", "the peddlers") was used as the default background music for the Game Boy version of Tetris, and is associated with the franchise to such a degree that, outside of Russia, it is often simply referred to as the "Tetris Theme". Other songs that have been used in the game include Ivan Larionov's "Kalinka", Tchaikovsky's "Dance of the Sugar Plum Fairy", and a movement from Bach's French Suite No. 3.