If we talk about achievement, it takes a lot of time if you are having difficulties with the camera angle. My simple suggestion is that if you want to complete some achievement, then play the game in "hard mode" two times, like the first time to complete the game and the second with infinite ammo to complete some remaining achievement, because you'll lose a game a thousand times if you don't like the camera angle at all, so better lose in hard mode than normal and easy mode.