well since i dont want to start a new thread im just going to hustle my idea here: a combo meter
as you play either mode, the meter fills ups. once its full it can be activated for something awesome and great (maybe in mono modes it can turn the gray blocks into colored ones for a limited amount of time, and the puzzles modes it auto-arranges your blocks for the same amount of time)
i dunno i think it would give you an adrenaline boost to just get a bunch of points at once, plus it rewards good playing