I truely loved the feeling your game gives, it works really well in all of its aspects !
I wanted to share some potential fixes you could possibly implement if you have the time and envy ofc:
• The stun that you get hit is a bit too long, the most problematic moment for me being the 2d boss : if you get hit in the middle of the room, you have high chances to get hit in a continuous loop
• When you die you don't respawn at the spaceship, I found it a little bit annoying (strong word for a little problem) because you have to get through the menu.
• Maybe the balance between sounds could have been cleaner but nothing that I couldn't bear :p
Other than that, I had a short but great time playing your game, congrats !