The sense of unshakeable isolation and unnerving despair GSC Game World's S.T.A.L.K.E.R. games instill in players can't really be found anywhere else. There may occasionally be other NPCs wandering around in the virtual space, claiming loyalty to different factions with clashing world views, but eventually you always wind up cold and alone on the windswept, irradiated expanse of the Zone -- the franchise's wasteland of a setting.
With tinned food, heels of bread, a few bandages, weapons, and ammo packed into your survival suit, it still seems all too little to ward off the brutal dangers and prowling, ghoulish creatures harboring unknowable intentions.