Monsters AI is like 5 years ago

[Zhobery]

You know, the scariest part of a game aren't the enemies, it's the waiting for enemies part.

They could have set one single enemy at the beginning of the game, and another one at the end, and I would have pissed my pants the same way, because I would have waited for enemies to appear at every moment.

That's what really scares you in games, and that's why games like Resident Evil (4 or 5) and Left4Dead, where zombies just spam from everywhere, aren't scary.