WorthPlaying writes: "S.T.A.L.K.E.R.: Clear Sky is a survival FPS game based on a 'what-if' scenario of the second Chernobyl Nuclear Power Plant accident. The game is created as a warning to mankind against mindless play with technologies. Clear Sky will run on a Intel Pentium 4 mit 2 GHz / AMD XP 2200 +, but is recommended on a Intel Core 2 Duo E6400 / AMD 64 X2 4200 +"