huh... Like MiB the movie:
Your soldiers act against civilian units.
Secret mission, civilians must not know.
Dead civilian: negative score
Live civilian: negative score
Stunned civilian (not a witness): positive score
is possible?
Maybe a special weapon that can respawn civilians (like zombies respawn as cryssys) to another kind of civilian: the brainwashed civilian.
if brainwashed civilian is rescued: positive score
if regular civilian is rescued: negative score
(alien must be present off course!)