You can play the game with three different characters: * Major Kira Morgan (whose visual design is based loosely off the character "Major" from Quake III) * Scientist Riley O'Connor * Sergeant Stan Blazkowicz (descendent of William "B.J." Blazkowicz from Wolfenstein RPG, despite appearances he is not the Marine of the original RPG, there were no known survivors of the Mars Incident. Though the Doom Marine (B.J. Blazkowicz III ) did survive.)