Autumn Aurora 2 it's modification made by small group from Poland which brings the autumnal atmosphere to the Zone and totally overhauls the graphics, audio and gameplay of S.T.A.L.K.E.R. Shadow of Chernobyl.
as far as i can explain and understand..
this mod is excelent..
graphics
gameplay
atmosphere (an eerie one, beautiful)
such a good mod made just for stalker that fits incredibly..
enjoy your game..