I remember playing a game with my parents when I was a kid (around 20 years ago) where you played either as the crew on a ship being invaded by multiplying aliens or as the aliens themselves.
The board was a series of rooms on the ship with the crew-members and weapons strewn all over the place. The part I remember most was that weapons had a random effect (picked from a pile), so you never knew if they would damage the aliens or cause them to multiply until you used one.
The goal of the crew was to escape the ship, and obviously for the aliens it was to kill the crew.
Does anyone know the game I'm talking about, or have I got my games mixed up?