Tetris (Commodore 64)

The Commodore 64 version of Tetris is one of the earliest-known versions of Tetris to be released.

It is most notable for its background music, other than that, it is one of the weakest Tetris implementations ever made. There is 1 rotate button, no hard drop, and no twisting of pieces at all. Even if the initial and final squares of a rotation are free, the piece will not rotate if it is against a wall.

Another version was programmed by Hungarian developers. It caught the eye of Robert Stein along with its Apple II counterpart, which triggered the release of Tetris outside USSR.