I love the atmosphere and visuals here. I think your game really shines in the art category. Really top notch presentation. I'd love to know more about how your implemented the visuals in the scene.
The game is a bit too unforgiving in my opinion. If you are really set on the sort of unforgiving difficulty level you currently have, I think you should consider at least giving the player a bit larger view so as to see enemies coming from further away.
Really beautiful submission, great work!