Very interesting game! I liked the different enemies and the eerie music. It was challenging but maybe having some of the enemies also shoot at you would make it a little bit more challenging, or maybe just the boss? Over all a very nice game, keep up the good work :D
I don't know if you've heard of Game Development World Championship before (gdwc2019) but it's a competition for indie game developers where they can submit their games and it's free! It's great if you want some more visibility for the game and it only takes a couple of minutes to join :)