Marine classes

Gasfiend

<div class="IPBDescription">Yay, i'm back again!</div>hey everybody,
sorry it took me so long to get back into the forums, computers troubles abound!  Anyway, i've got a new question to start you guys off on, i know the aliens have their own seperate classes, and the marines have nice fancy gadgets to play with, but do the marines actually have the ability to level up the way the aliens can, or do they gain special weapons or abilities as the game progresses in any way?  Oh speaking of which, since you guys have been showing us lots of nice marine gear, lets see some alien goop, trust me, change is good!
Gasfiend
Oh, and how do i get neat little mini-pictures on the side of my..thingy...underneath my name...
"Where am we going?  And why am I in this handbasket?"

Moleculor

Marines can be improved by the commander, similar to the aliens, but whereas the aliens upgrade individually, the marines upgrade as a team... or at least that's how it's been explained (the commander might need to spend a tiny amount to give the new abilities to newly spawned marines, but...)

For the avatars on the side, or the sig below, go to your control panel up in the top left.