I disagree with the other commenter. You changed the gameplay halfway through, which suddenly drastically changed the dynamic of the enemies! The room where I couldn't move and had those things shooting at me from both sides was a much harder boss battle than the actual boss! This game got really complicated from just an axe that you can beam yourself to and the generic chase-and-shoot enemies you see in every top-down shooters. Great level design btw.
That said, if you wanna sell this game for money, here are some suggestions going forward:
-More enemies. Obviously.
-Death animation.
-More musical variety.
-And more levels! I could play this weird game all day. Please let me.