JUST REALIZED DEPT: ALL First person shooters are really Pac
   Man. The difference? You never lose your Power Pellets and can
   always eat the ghosts. [kill your enemies] at least until you
   run out of ammo or if they're stronger. Then you lose your Power
   Pellet ability and they can kill you.
   Shoot your enemy, eat your enemy, Get killed, get eaten, not
   much difference except the mess.