I really liked the retro style and the music.
Other than that, I was a bit frustrated when the final boss disappeared for a while. I thought I was stuck, but it eventually came back for no apparent reason.
I was getting ready for an intense fight where I'd have to dodge attacks while fighting back, but the boss ended up getting stuck in a corner, so I defeated it without much effort.
I think it's a concept worth developing further. Overall, I enjoyed the experience.