It sounds like a lot of what you're looking for will be in this game, from what I've seen of the trailers. Yeah, it's not exactly what you want, but it will be a lot closer than AVP. As for the different alien types: great movies don't always make great games. What works for a 2 hour movie may not work for a 12 hour game. Having a variety of aliens means variety in the tactics used to dispatch them and get through the story. That will better hold the player's interest.