Great game, I managed to overflow into negatives before having to hand in points. After attempting to hand them in they slowly increased to 0 after which I got softlocked (grayed out hand in button).
Possibly intended mechanic that got me to overflow
When you double points with a monocle, they revert after a transmog. This is not the case when the item is eaten by a vampire. They are quite rare, but I cloned them with the consumable. Combined with juices and monocles I could 16 384x the points per vampire.
However after I kept a vampire with permanent stats about -2^63 it got reset to 0 without affecting my points. Maybe the first time it was due to parrots?
Other than that there is an inconsistency where most active effects can affect themselves (including bomb and transform), but broom cannot destroy itself.
I’d also appreciate an option to speed up animations, though that’s only necessary only after you get enough points to stop caring about rounds. Skipping a round takes a long time even if you leave the board empty. Though perhaps this is just an issue with there being a single (mostly consistent) strategy that is exponential while other strategies are not at all