Tetris
PLAY !

  Left - Move shape left
  Right - Move shape right
  Down - Faster drop

 X or Rotate clockwise 
 Z - Rotate counter-clockwise 
 P - Pause/unpause game 
 Q - Quit game 

Most people have come to know Tetris through hours of playing on the Game Boy. But the real hero is a one Alexey Pajitnov a Russian genius with too much time on his hands and an affinity with beards.

For the Tetris novice: shaped blocks fall into a pit where you must arrange them so they fit neatly a sort of juggling in one direction. The more blocks you can place into a horizontal line simultaneously, the more you score.

And remember to take a break every few hours.