1) The third in the Castle Wolfenstein games. A FPS created by id Software. You play as BJ Blackowics and you have to escape Castle Wolfenstein, killing Nazi's along the way. You also have to kill Hitler.
2) Gave birth to games such as DooM, Rise of the Triad (which was also reffered to as a sequal somewhere) and is followed by Spear of Destiny.
Castle Wolfenstein, Beyond Castle Wolfenstein, Wolfenstein 3D, Spear of Destiny, Return to Castle Wolfensteinh
Wolfenstein 3D (often incorrectly credited as the first, first person shooter) is an FPS game for DOS computers created by ID, who are the creators of DOOM, as well Quake, and even FPS games before wolfenstein.
The game consists of fighting nazis, mutants, dogs (or giant rats in the crappy nintendo version) and several larger boss enemies, including Hitler and Hans Grosse.
The game is extremely historically accurate as well.
I am playing wolfenstein 3D blasting away nazis with a chaingun, woot.