We kept dying over and over again at the very first Level-Up Tower in multiplayer, until Morale got so low we needed to remake the world. Right now there's just 2 of us, may be up to 4. We didn't have any problems with the default difficulty of the original AVWW, actually increasing it as it was way too easy. And it's not like in AVWW2 we can easily powerup some other way than beating Level-Up Towers (it penalizes us for additional purification).
So on the subject of difficulty, can we please get difficulty options for AVWW2, available at the start of the game? Maybe we can raise them when we understand the game better, but right now, it's just far too frustrating to play on multiplayer at the default difficulty.
I think AVWW2 looks great in single-player, but in multiplayer, the rather linear setup hurts it. In the original AVWW, everyone had a grand time exploring on their own and completing tasks in small groups. In AVWW2, we have to do all content together, because stuff like purification takes up a global 'turn'.
Note: Each enemy projectile was taking off roughly 0.4-0.8 hearts with one other person. Some projectiles were indestructible and nearly unavoidable, like the homing ones from robots.