This game is very difficult to play successfully, unless you are a hardened, seasoned gamer. Anyone new to FPS games (First Person Shooters) should steer well clear of this one. I made the mistake of buying it and I have had nothing but failure, disappointment and exasperation for just about all of the gameplay. To my mind there are three major failings that make this game so difficult. First, there is no 'Easy' level of difficulty, only 'Normal', which might as well be 'Very Difficult'.
Second, there is no regeneration of health. Once you lose part of your health, you can only lose more, until you are inevitably killed.
And third, there are no checkpoints, where your progress, if you make any, is marked. If by some miracle, you get most of the way through a mission, but fail at the last moment, you are dumped right back at the beginning again. Believe me, after twenty, thirty, forty.........attempts, doing the same thing over and over again, it gets very, very, tedious and frustrating.
Unless you are happy to do the same things over and over again, with very little reward, fun or success, avoid this game. Spend your time doing something comparatively simple, like learning another language. You'll accomplish more than you will with this game.