It looks like low quality stops whatever timer(s) is used for calculating dps... so if the machine isn't completely overloaded, a few seconds of pending cash loads up on a stopped timer, spiking DPS used to increment score. It also seems that DPS events queue up while in low res. So, let it sit a while in low, then toggle between hi and low (a few seconds). I've ended up w/ $170M+ DPS on 40 boards.
This is a fun game, although collision detect is shifted 1/4 torch length to the left, and fails to trigger if the fireball is fast enough. Fix those bugs, and you've got a cool game.
No comment on the 60 pointer, other than it's a best-time metric, not a single-run metric.