
I've done those sorts of things. Problem is there is a weapon level cap for certain difficulty settings. I want to get to 70% completion to unlock the abilty to use any weapons on any setting, but 70%, I think, requires multiple playthroughs.
I played as Wing Diver until I got enough armor for the achievement. I wonder if, in co-op, whether weapon pickups go to both players? I'm thinking yes.