Couldn't try the multiplayer but some interesting concepts I haven't seen before, the flipping mechanic is pretty cool but I don't know why you snap the camera 180 degrees on a flip, makes it much more disorientating than it would ordinarily be. There's some major stuttering issues in the web build that I think happen each time an enemy spawns? Seems like it could be avoided with object pooling potentially if it's an object instantiating related hitch. Made it pretty brutal to play.
I solved 3/4 rooms but couldn't figure out the button room, I pressed all of them but nothing seemed to happen? I'm a little lost still.
Really cool central mechanic though, definitely a puzzle game you could make around this, pretty sweet to have a full 3d environment made for this as well with a variety of props too. Although it was a teeny bit too grey, a bit more color would be sweet, maybe each room has a signature color to help differentiate them a bit more or something.
Awesome work!