Till today, this is my base line for AI in shooters. Sadly, I have not encountered any that manage to top it. It is a game that challenges more with the behaviour of the enemies, than with high damage or soaking bullets. You try to stand still, the enemy will try to flank you, while providing cover fire. Enemy has metal plates? Well, better don't shoot at those, won't go through. Precision and fast decision is, what will win this game. The other part of the game well done: It frightens you more than it scares you. That is probably depending on the person playing it, but I personally can't stand those horror shooters that at every corner fling something unexpected at you, just so you flinch. (Like Monsters dropping from ceilings, breaking through walls, etc.) A bit of nostalgia is probably mixed in this.