S.T.A.L.K.E.R. Clear Sky is a frustrating and hard game. It is not really for casual gamers and requires some real commitment to build your skill level to the point that you actually find it enjoyable.
It is the prequel to Stalker Shadow of Chernobyl created by GSC Game World. The story is a standard post apocalyptic nuclear wilderness. It is a multiplayer and singleplayer game that runs on the PC.
The game is a bit buggy and sometimes crashes as well.
Your Best Weapon in Stalker Clear Sky the F10 Quick Save Key
If you get into trouble the F10 Quick Save Key can really help you out of a jam. Enemies bent on your destruction suddenly become confused upon your return. It is almost like a get out of jail free card in abundant supply. So I would recommend S.T.A.L.K.E.R. Clear Sky after they release and update to prevent crashes and bugs but only if you press F10 alot and maybe with some cheat codes.
Hilarious Video Review of Clear Sky Game:
Game Features
1. Many different endings
2. Freedom from the storyline
3. Cool atmosphere and weather
4. Map editing and creation