Here's what I know:

I think it came on a MacFormat Magazine CD.
It might have been freeware, was most definitely shareware.
It had tiny graphics, top-down perspective and was a turn-based game (not sure about this...) using movement tiles.
It used an Aliens theme, and used SFX ripped from the movie, such as gunfire, quotes from characters, and aliens screeching.

Would love to find something about this game online... anyone remember this?