The great-grandaddy of first-person shooters, Wolfenstein 3D, today celebrates its 20th anniversary. Released in 1992, the game gave rise to a fledgling studio of plucky young upstarts called id software, who later went on to make a little game called Doom. (Perhaps you've heard of it?) While that game is perhaps the better known of the two, Wolfenstein 3D is considered the birth of the genre that