I like Player1's idea, as usual. But I would like to suggest a tweak to it. You woul be given a score for damage dealt, dretches of course, would have a small bonus, 25, where as a tyrant would give a much larger bonus. My suggestion is that you lose points for damage taken. The aliens are going to get much more points, but with their healing ability, will be able to ake much more damage. Perhaps structure damage should be X2, to encourage gameplay, instad of killwhoring.