I've never seen it before, to be honest though I don't see this being a successful model. The people not playing every day are already those who are not really

I've never seen it before, to be honest though I don't see this being a successful model. The people not playing every day are already those who are not really hooked on your game, I think most people that come back to a game after "unpassing", would probably just quit the game entirely, and anyone who shells out for the levels they already beat will probably feel resentful.