You can also play mission 5 with Xeno - It just takes a little longer xD At the end I wanted to play a little with Xeno but she obviously had another appointment. Have fun!
I have lost count the number of times I have played this game through yet watching videos I find myself ducking and leaning in response to the events more than I do playing the game myself. That is a signature of genius in the making of a classic game that holds up to the original movie.
The Alien will realize you're behind a physical barrier, upvent, and look for another way to get to you. In some rooms that's impossible (like those private rooms in medical) which means you can kind of exploit that to put the Alien backstage for a moment and move yourself around some more. This game's AI is really damn good, but just like any other, you can still learn to work around it.
You are a great player but that waiting for the last moment to close the doors made me cringe, hehe. Really enjoyed how you were making the Alien your bitch... Until you weren't...