Androids have been a staple of the Alien franchise ever since its inception, with the most memorable iterations being Ian Holm's murderous Ash, and Lance Henriksen's unexpectedly heroic Bishop. Though it might be a stretch to have another mission where the Marines are accompanied by an android, what about coming across one (or the remains of one) during the missions, infusing the player with some brief paranoia, as they won't be sure whether to trust them or not. Another slightly more outlandish option, of course, would be to have one of the Marine characters turn out to be an android, but as we say, that one is pretty out there.