Hi @Guy!!
Multiplayer is not an option at the moment.
Despite this, it depends the game you are designing. Imagine you should move a sfere through a road, like a labyrinth. Yo can set the camera on the top and set “a w d s” to move red ball, and 
to move green ball.
Finally if green ball collides the finish line before red, green wins one point…
I’ve never do this, but I think it can works as a multiplayer game.