In the 80's me and a friend use to play Awful Green Thing from Outer Space
(no pun intended on my log on name) every chance we got.
Had a game just a few months ago, it's still the best SF gme ever.
A great board game. (2nd to Chess but only just).
They should do a computer version.
http://en.wikipedia.org/wiki/The_Awful_Green_Things_From_Outer_Space