This game is not for the faint of heart. Don't expect to go in being able to run and gun. You'll get shredded instantly. You have to be tactical. Which I don't usually like and haven't played much of this subgenre of fps but for this game it works. The atmosphere is the best part of the game. It really feels like you're in a desolate wasteland and you have to keep track of your supplies, (health kits, bandages, weapons, ammo) more closely than in other fps games.
It was frustrating at times as the game wasn't ever finished being made completely but if you can overlook that and the occasional hitching this game is a masterpiece.