Well I have finally begun my Nightmare runs in AVP and it is turning out to be way harder than I imagined at least on the Marine missions. For anyone who hasn't played AVP the Nightmare setting is the hardest mode where you don't get any checkpoints in the level, so if you die you have to restart the entire mission.
Walking through the colony and having the motion tracker pick up several signals creates a very tense situation. Last night I finished the first level of the Marine missions (took about 45mins) and the last bit has you holding out in a long hallway vs a ton of Xenos. My pulse rifle chewed through the first bit before they even got off the roof, the second wave well they got closer forcing me to melee the first one in the face and then sprint in the direction they were coming from so I could kite them some more. It sounds easier than it actually is, the Xenos have a tendency to jump around and are very good at flanking you, the key is to have a path in mind when backpedaling away from the Xeno and then when you have no more room to back up run like a mad man then rinse and repeat; Worked pretty well for the first level, hoping I can have more success with the second level and hopefully by the end of the week I will have completed Nightmare on at least the Marine side.