Finished the game in 8 or so hours and it was a remarkable experience! The tension really ramped up after a couple and remained throughout. I didn't find it outright scary but you were always on your toes with the overall atmosphere and not knowing what you were walking into next. There were plenty of challenging combat encounters and I really enjoyed the gunplay and general mechanics. They really don't make shooters like this any more. If this was a modern game it would be x-ray vision, checkpoints every 30 seconds, enemies with vision bars, grenade indicators, minimap and weapon skins. This is definitely up there with the likes of Half Life 2.
I now have TWO expansions to sift through - not shitty 30 minute DLC's like we see today, these are proper expansions old-school that you used to get on separate discs! I'm still in two minds about getting F.E.A.R 2 as I've heard it's nowhere near as good or unique.