Modpack, pausing, and flying are disabled. However, click and you can collide with your partner. MOBILE PLAYERS: since you need to touch the screen in order to move, collision with other players gets activated every time you try and move. this is something I did not consider. however, there is an easy fix. while you are trying to move, you can deactivate collision by simply tapping the screen with another finger.
you can't do this one on your own. come back when you have a friend to play with. and when you do, make sure you are rubber banded to them.