Played this coop a bit tonight, it did not click. We played like four "runs", never got past second floor. Didn't understand anything. Whenever we died, it kicked us bad to the start with no items. Also we didn't understand how to use the equipment we spawn with? Like the Halo Guy's ammo drop? Meanwhile, we got like one gun per floor, some of which weren't even useful. Only ever got one health drop at all...
So what gives? Are there supposed to be checkpoints in this? Is there any kind of permanent progress? I wouldn't mind the difficulty so much if I wasn't spending so much time with that little junk-ass nerf gun.