Play the Tetris game.
Shapes drop from the top of the screen, and the user has to move and
rotate the shape to fit in with those at the bottom of the screen so
as to form complete rows.
tetris-mode keybindings:
Uses keymap `tetris-mode-map', which is not currently defined.
M-x tetris-start-game Starts a new game of Tetris
M-x tetris-end-game Terminates the current game
M-x tetris-pause-game Pauses (or resumes) the current game
M-x tetris-move-left Moves the shape one square to the left
M-x tetris-move-right Moves the shape one square to the right
M-x tetris-rotate-prev Rotates the shape clockwise
M-x tetris-rotate-next Rotates the shape anticlockwise
M-x tetris-move-bottom Drops the shape to the bottom of the playing area
(fn)