When I saw the gameplay I was relieved to see that people don't just run away screaming and crying as soon as there's the slightest hint of something unknown lurking around, like in AvP2. It just made it into a mindless slasher. Now you can actually walk on a dark roof just above peoples heads without being seen - just like you would be able to in real life - Instead of being instantly spotted and shot at by a completely stationary marine who you then proceed to mindlessly kill and eat, rinse and repeat until the level ends.
I hope they also didn't design the levels to be like AvP2 where, if you got lost, you could easily spend 5-10 minutes just walking around the now familiar-to-the-point-where-you-just-feel-like-quitting level until you find that magic opening where you were supposed to go all along, but since you didn't find it when you were supposed to, got stuck going in circles.