That's pretty cool, I like it very much :-) But the left one of the gun guys seems not to recognize that he is under attack, lol. You should have turn him around into direction of the monster.
The entire work is a very nice idea. Although I wish, the left trooper would have more interaction with the geenestealer. The highlightning is a little bit too strong for my taste, or otherwise it had to be shown on the floor and the wall and pipes as well. In total a 9 for the scenery.