Great graphics and atmosphere - but the gameplay is lacking
The primary problem with the gameplay is the RPG elements, which, as mentioned by another reviewer, feel like a chore and take away from the firefights. Perhaps if there was better transportation than running available (which is not even possible if you have too much gear) then this wouldn't feel like work, but I really would like less chit chat and the like between actual fights. Also, the game forces you to worry about all these extra aspects that I don't really feel work well with a first person hsooter game (e.g. radiation, artifacts, food, gun wear).
The positives of the game are led by its atmosphere and great graphics (provided you have a good system, because it doesn't scale well). It truly feels depressing and bleak, and the developers really hit the jackpot in conveying the ambience of the zone and how it is a desolate wasteland. The AI is excellent, and it can be a challenging game on higher difficulties, so you need to be slow and stealthy instead of going rambo.
Overall it could have been a masterpiece if the game focused more on the FPS elements and didn't force you to bother with all these non-combat aspects that are not really enjoyable. Also, as reported by many users, there are a variety of technical problems, and you need a pretty high-end system to get the best graphics out of this game.