Firstly I would like to give the GOOD points. This is the 2nd game in the series,(although a prequel) the 1st I have not played, but this game is making me think about getting the 1st.
The Atmosphere in this game is, simply put, awesome. Dark creepy landscapes full of monsters at night (STOP!! Don't turn up your gamma! its worth it!), special effects when encountering Radioactive areas, chemically desolate areas, and humming annomally fields make you feel sorry for the citizens of Cheynobel even though this is fiction! 9/10 for atmosphere (top slot is reserved for F.E.A.R). When its night time I recommend closing the curtains, or turning the lights off. It will scare the hell out of you!
The story is also worthy of a Sci-Fi epic, although possibly more work with factions and characters would have been appropriate.
Graphically, it is a fantastic game, one of the best I've seen recently, however you WILL need a fairly decent gaming rig to experience it; a high end dual core processor or a quad core is recommended, with a £200+ graphics card, should see you on Very High settings with a few tweaks in the Advanced graphics section. Another thing that stands out is the Artificial Intelligence of the computer foes - in short, pretty damn good, the sly rats! Enemies will run to hide, shoot over boxes etc, and frequently change position.
Gameplay: Apart from the AI mention earlier, the game play is fairly open; you can do whatever you want in whatever area, although access to some areas is only possible with plot advancement. However, this game is great either for the game plot hammerer, or the pottering-about-get-everything-explore-everything-gamer. Pretty much free form. However, this game is, unfortunately bugged to a fairly annoying level, although the latest patch (1.05) manages to sort a lot of them. However I noticed several annoying things like equipment you cannot find EVER, and tasks you can never complete due to characters disappearing. Sometimes the plot line will just die on you and you can't take it further, requiring a reload. of course these bugs aren't there all the time, but occasionally you think an Annomaly has drifted into your hard drive...
In it's defence, there is a community of game modifiers (moders)out there that have added "mods" to the game which fix a lot of things and indeed enhance them.
Endgame: Challenging, but do not expect a huge explosion and mankind to be wiped out as you stare at the screen in awe. Remember, this is a story with more than one part.
Overall, I loved it, despite the annoyances of bugs, and its got 4/5 Stars for story, atmosphere and gameplay (sans bugs). But its 7/10 for bugs, something which in recent years has annoyed me with PC games; The get-it-out-fix-it-later policies which MUST change, Mr. Software House!! Get it right first time will you!!