Hi I am new here lol.
I have couple of suggestion about tremulous from Alien prespective.
1.) The infestation you know that black ooze that comes from the building on the ground it would be awesome if Overmind could produce a big area with that ooze and also that eggs could produce a little larger area.
It wouldn't affect the gameplay but it would really gave the feeling of some sinister infestation.
2.) New build time icon. because humans and aliens have the same icon when building.
3.) Claws, legs or even mouth on the screen when you are an alien for attacking kinda like alien vs predator while being alien.
4.) New models for Dragoon, Tyrant and ganger so they would look more scary like
Kinda like tyranids from warhammer
http://cache.kotaku.com/assets/images/kotaku/2008/08/tyranid.jpgMarauders and basilisk are really scary because they are colored spot on.