Completed 3 levels. I got lost a lot. I also died a lot while my co-op friend didn't die any (that I know of). Time to change strategies...
Alright! It was tough as I had a hunter alien on my heels the whole time, but I was able to reach Nicole, who was attached to the Marker. I defeated her (eventually) and made my escape with Ellie. What a cool game. Final boss and game ending! Great stream!