There used to be a general rule of thumb with certain types of gun games. You had run and gun shooters that were all about visceral violence, where the thrill came from pumping lead into the nearest up-springing bad guy.
Then there was the cobwebby, creepy corner of survival horror where although you'd still aim down the barrel of a six shooter. The pace was slower and it was more about building tension with the occasional 'behind you' moment - rather than mowing down all you can see with a smokey machinegun.
It's because of this clear differentiation between the two sub genres that F.E.A.R and its forthcoming sequel F.E.A.R 2 is of particular interest.