I really love the concept of accumulating a lot of power-ups to become stronger and stronger!
It's a bit sad the game is very difficult: I've lost twice against the second boss, the bird, and I didn't have the courage to try again ^^'
It's because hitboxes are not very permissive for the player, and bosses are sooooo long to kill (20 hits for the first one... !).
If you plan to continue this game development, I strongly suggest you to lower enemies HP, and give some bonuses to heal player after a boss fight.
The concept is so neat, I would love to see more power-ups: so please let bad players like me enjoy your good ideas by making the game more accessible :D