NEW THINGS
But as this games are concidered to be simulations,it would be logical that new things are being discovered as game time passes.
Imagine the houses to invent new class fighters,new weapons as you level up.Further more how about you will be able to design your own ship figure from predetermined ship design parts.
It is also logical that new bases are constucted also.
I can think of a few other things(mission:destoy a base with a nucrear warhead),but I believe you have already thought it first.....