ok so I got a few things:
First, did you change the purple lighting to yellow? Bc that's what it shows for me. I would like to see more levels, as I like the feel of it. With those new levels, I'd like differentiation in the colors and themes of the levels, so it doesn't get boring. I'd also like hearing some enemy noises, as it feels very barren without them. As for music, the genera that would fit the most is probably a combo between techno and metal. It would sound awesome!