Well.....I'm half-way through, very good FPS I must say. One small thing which I don't like about it is that ammo doesn't remain in storage i.e. when I replace a shot-gun with a sniper rifle I also drop all its ammo so if, at any later stage I want to go back to the shot-gun I'll have to start gathering ammo all over again. In other games you normally only loose the number of bullets remaining in the cartridge and the rest stay with you, not so much here.
The scare factor also decreases as you advance, level 3-4 was
somewhat frightening with the dark underground facility and the weird monster, but now that I'm above ground, it doesn't seem much different from a CoD game.
Still give it a 9/10 though =D