Might give it a go using multiplayer, but having completed the single player, I'd say that the platforming is workable although a bit floaty. Its a bit tedious to die and have to traverse empty spaces again and the level is kind of huge. Enemy design was pretty cool. Needs some sound FX though. Pretty ambitious for it being online multiplayer so props for that!
Btw for skull enemies, running away and quickly turn around to shoot them is the way I used to dispatch them. Some mad skills required!