
To go with my tic-tac-toe hats. The pink that's transparent, you can walk through, pick your place with a specific button(like space). The pink changes color to the persons team, X- blue, O- red. the exit is at the top, 2 player mode, 9 player mode. Not sure about the exit though, what if someone leaves? in two player mode each slime picks there place with the button, taking turns, in 9 player mode, its the same, just each slime is frozen in place as the pick.

Maybe team chat in 9 player?
p.s. on top of the door is the blurred text, "Exit",
EDIT: made more specific in an area.