It could use a bit more work.
The fights were a bit bizarre, but understandable after a few rounds of trial and error. The platforming can be very frustrating after the fourth boss as I found myself sliding down the floating slopes and apparently couldn't jump or double jump back on before my plunge.
I'll be honest, I wanted to play through this game only to hear the music. I couldn't finish the game (so I don't know if you added credits to it or not), but it would be nice to know the music source of the bosses.