Really well-made for a first game. I like how frantic it gets deeper in, even when it just gets me killed.
One thing I noticed in my playthrough is that some of the enemy shooting audio overlays with itself in a way that's kinda grating when a lot of the same enemy are shooting one after another in a quick sequence. I wish I had a better way to describe it, but alas, I'm not an audio engineer.
Also, I died while using the raybeam, and when I came back, it was still going. I'm not sure if that's meant to be a mechanical forgiveness thing, or if it's a bug, but I thought I'd mention it.