Tetris is a video game developed in the Soviet Union in 1984. The goal is to drop blocks, called tetrominoes, down into a playing field to make lines. Tetriminoes are made of four connected squares each, and there are seven different shapes of tetrominoes. A player uses the tetrominoes to make unbroken lines of squares across the bin from left to right by stacking them in the playing field. When a player makes a line, it clears. After a clear, squares over that line fall. As play goes on, the tetrominoes fall faster.
The goal is to drop blocks, called tetrominoes, down into a playing field to make lines. Tetriminoes are made of four connected squares each  There are seven different types of tetrominoes. Levels have a set goal, or number of lines to clear. When the goal number reaches zero, the player moves to the next level. As the levels go up, the tetrominoes fall faster. A player receives bonus points if he can clear more than one line with a single tetromino. Clearing four lines is called a "tetris", three lines a "triple" and two lines a "double".. Clearing two tetrises in a row is called a back-to-back tetris. The player can also turn a T-shaped tetromino into a hole, called a T-slot, to get more points. This move is called a "T-spin". A player loses when the tetrominoes make it to the top of the playing field. See "Issues" for information on the Level 29 Problem.
On the Game Boy, there are several musical themes played. The theme for level 1 is often called the "Tetris Theme". It is actually a Russian dance called Korobeiniki, or "the Peddlers." Other themes include music by Johann Sebastian Bach and the Dance of the Sugar Plum Fairy.
When one reaches Level 29 on the GBA or DS, the level starts to offer pieces that seem to fall indefinitely fast, hence disallowing the player to move in a lock, or quite possibly, move the tetrominoes at all. This means that all the uncontrolled pieces will pile up on the playfield and cause the player to top out.