Oh, since i have your ear, here's some more! Projectiles still fly when you have the upgrade menu open, there are even damage numbers! (I assume this wasn't intended.)
Also, if it was up to me, i'd bind the dash to Space by default. Doesn't seem to be used for anything else, and the thumb is more resilient than the pinky in my experience. Though, obviously, if control settings are planned, this is a non-issue.
Edit: When the wave is over, and there are no targets, bouncers seem to create lag. Maybe they keep checking for targets as fast as the CPU allows or something?
Edit 2: After beating normal in the forest, i selected "endless". It immediately ended and rewarded me. I could select "endless" over and over again, for more rewards. This didn't happen before.