I say it simple i want a STORY , like the eath was destroyed by planetoid or comet impact , the humans gonna travel new world , and here we have the aliens or in underground bunker humans fight for survive with aliens....   Something cool and creepy

Tremulous does not need the story. But we have theme maps with story https://www.kickstarter.com/projects/aaagames/tremulous-2-0/posts/406374

Big true, tremulous is mainly on gameplay not story, it would need singleplayer then.

A few stories have been written (I wrote one), but it's mostly along the lines of what you mentioned.

I Mean short animation on start of the map

These stories are good (: