FYI - you don't get anything at all if you quit rather than lose from what I can see)
you get "participate in GO" completed the very moment you start the first battle i think, so this one u will get anyway

for me, while i managed to clear Crom (scoring soul survive and 3 sr too, since i have only Shiva and Aphro as water SSR's anyway), scoring the "5 alive" and "with Arthur" are beyond me (for my water team now, at least).. need to slvl a bit more

oh, and idk if it was mentioned here before, beware the second wave middle mob (nukes insane single target damage) and fourth wave middle mob (multinuke) as well. i killed them firstly