Most notable for its background music. It is one of the worst tetris implementations ever made other than that. 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 peice will not rotate if it is against a wall.
Another version was programmed by Hungarian developpers. Catched the eye of Robert Stein along with its Apple II counterpart, which triggered the release of Tetris outside USSR.