trying to understand the many buildings vertical architecture you are walking to localize yourself and survive to the many guys shooting you. the act of shooting, itself, is an act of surviving: the one who shoots first is the one who gets to live, just like the old west. this concept of "shooting before your opponent gets the hands in his weapon" creates a cinematic experience way better than many today's cinematic shooters - probably because the one doing the scene is you, with your reflexes, paying attention to enemies animation, not the game, desperately, screaming "look at me".