Amazing work creating a boss fight in just 3 hours! Really enjoyed the gameplay factor of the game.
The weapon sacrifice is a brilliant idea to add difficulty progression to the game---however, for most of my gameplay I used the bow mainly. To be honest, I'm not particularly good at boss fight/bullet hell games so I haven't defeated the boss after my weapon sacrifices yet, but I will hopefully have time to play the game again before/after the jam ends!
One small Issue I found was that the shield does not work on my side---I couldn't use the shield. In addition, I suggest a full screen mode of the game, as the itch browser tends to behave weirdly with games that require mouse control. However, this is not yours or the game's fault at all.
Great job!