Well made! Had a lot of fun with the enemy waves. Reached the boss on the second attempt, but couldn't clear it. Most of the time I had enough mushrooms, but was forgetting to heal. I think the difficulty curve was alright. You could consider adding more attacks in future, like area-of-effect, push-back, etc., plus more variety in enemies too. Also maybe an option to upgrade health as well. Sometimes I felt the wave got completed although I could see an enemy still standing. The lore, sound and graphics are coherent, and give a good setting for the fight. Nice work!