i really like NS, i think its the best made mod out there. The commander has a chair he climbs into (anyone can do it) when your in there you have an overview of the map can can place out structures and such
Hmm .. I just thought of another thing:
At the end of the sequence with the buggy, gordon jumps out of the car and starts blasting that flying thing. now when he hides from its fire behind the tank / car wrecks and it hits the cover insted, you can actually see the sparks through the vehicles...
I think i noticed some antlion corpses disapperaring in the part where hes in jail throwing around those scent bombs. At the end just before the large one comes out you see a corpse and when he backs down from it, its gone