S.T.A.L.K.E.R 2 is a unique blend of FPS, immersive sim and horror with a really thick atmosphere. One of the biggest open-worlds to date is yours to explore — along with an epic branching story with multiple endings. S.T.A.L.K.E.R. stands for (Scavengers, Trespassers, Adventurers, Loners, Killers, Explorers and Robbers).