I really like this. The visuals are like something from a fever dream. I love the song, too. Great atmosphere. The wall jumping felt good (though the acceleration was a little intense) and the attacks were impactful. I hope you get to continue on because I feel like this could go somewhere interesting :)
I had the same issue as some others with movement but when I realized it was dpad and not joystick I was good to go.
One problem was the area transitions-- when I'd try to fight the boss, the scene would load in, and then immediately load back to the previous scene and drop me on spikes :( I didn't actually finish because of this as I'd have to redo the climb from the mushroom beforehand which was tricky. The enemies respawn a little too fast for me too.