Hey congratz! Your game is very nice!
I loved the art style, the gameplay is very fun and you also took the time to write a story around it, great. It was a nice discovery and I enjoyed playing it to the end boss. Personally, I think the difficulty was good.
The music is also nice and catchy .
The only thing I would improve is to add some sort of animation when you hit an enemy (and especially for the boss). When I was fighting the boss, I was not sure if I was hitting him or not.