key input exist in rm, no need for it cause rm can check positions, facing, button pushing
with all combined, with a hella good eventer with too much time , you will still lack the basic thing-
3 players live on a small screen, even if we made it so that the screen will follow the rest of the players too, and we could, the screen will always look on 1 player of choice, and the others will walk blindly until the nice screen will remember going back to them.
so the best you could do is a map so small it won't allow any player to leave the screen range
yes some mini games can be made like that, but they will be a bit too limited
(or othereise turn based... yay rm monopoly Oo)