Saw that you updated this and decided to give it another spin. I don't think the masteries button worked in the previous version I played, the game is definitely more fun when you use them. Upgrades are solid and fun overall but could get a lot crazier. I still think the tempo is way to slow. I increase my movement speed every chance I get but it's still way too slow. Double speed of both characters and monsters. perhaps even more, from the get-go, allow speed upgrades to make it truly ridiculous.
A lot of time you are moving away from the enemies while firing backwards, this creates a kind of weird constant turning for the character, something to consider.
Regen makes you effectively immortal at this level of difficulty, might be good to know for balancing.
Grab range is not fun as an upgrade unless you make it much bigger each time.
Suggestions for enemies:
Design on slimes is cool, let them volontarily split and launch the smaller one at you.
Give big hungry guys something more than pure movement. Let them plant bomb girls bomb occasionally.
Enemies which fires beams, charge up animation, small red line almost like a laser sight which tells the player to avoid and then big beam time.
Suggestions for upgrades:
Upgrade that makes bullets move in different patterns
Upgrade which makes bullets split on impact with enemies creating a splash effect.
Upgrade which makes speed of travel for bullets faster.
Upgrade which makes bullets occasionally spawn a cat for the witch which acts as a turret for a limited amount of time, a bunny for the elf.
Completed a run with each character.