I fail to see the point of this. I can paint exactly one square and then wait for 5 minutes while nothing^H^Hbarely anything is happening? I can't doodle anything meaningful without filling at least 5x5 area, and I need to spent at least two hours for that.

I think this could be more attractive if done as a turn-based play. Fill a square within, say, 10 sec and then wait until everyone currently online finishes their turn. And so on.