This is a comment to warn people about known issues with the jam build:
If you line up on the Y axis with the witch when she shoots a bullet at you, the game can crash because it divides by zero. To avoid this, I'd recommend attacking the witch from below with the sword and diagonally with the flail.
Jumping in place next to spikes can cause you to fall into them. For this I'll give the hint that you don't actually need to do so to solve any puzzles.
Enjoy the game!