I saw the difficulty after seeing other people feedbacks. I've played my game hundreds of times, so for me, I knew how to play naturally to counterbalance these drawbacks. So I've adjusted a few things in the new version and it should be better for now.
I also understand about the last part, but like many of us, i was running out of time and i really wanted to challenge myself on every part of this game, first time i work with pixel art, even for the music I made myself. That's why I couldn't do the last part with a fight against the Kaiju (which would have been even more fun for sure). Maybe in a future version.
And thank you for your feedback!