Tengen Tetris is a version of Tetris made by Atari, which pretty much follows the basic formula of stacking tetrominoes and completing lines. One difference, however, is a Cooperative mode that allows two players to play on the same board simultaneously. The board is 12 tiles wide in this mode, rather than the usual 10 tiles.
In this run, the author controls both players and completes just the final level, level 17, as quickly as possible.
Watch this run being played back on a real console.