Managed to beat on my second try! The things I liked the most are the graphics (beautiful) and the controls (smooth)! The boss designs are also very cool. I have one suggestion. I realized that if you stay close to the bosses and just spam sword attacks, they die really fast! The exception is the boss of the Forest, that shields itself for a while until the player destroy the mushroom's spawns. My suggestion is to maybe remedy this by adding different patterns to the bosses or something else.
That's it! Great game!