Beautiful game, and beautiful music. Really like the minimalistic color palette, and the white on black theme. I was thinking in my head that you would need some sort of checkpoint system because the trek back was a bit tedious, and then there it was! Also fun with a boss at the end, and nice with clear telegraphed attacks. I feel like difficulty has been very hard to gauge (my game turned out way to hard) but yours feels pretty well balanced.
Some things that might have been nice is to maybe outline the scrap with a tiny lighter hue, didn't understand the scrap was the thing I was supposed to pick up until a couple of platforms in when I finally noticed the prompt.
Also, on a "if you were to continue on this after the jam" note - On my final stretch on the third floor I found a bug where punching the air where you've killed an enemy it keeps dropping energy indefinitely. So with that energy resource management becomes a non-issue.
Very good job!