Cool vibe and game!
I did find the spot where enemies stop following you early on, it was really hard not to want to hide there and snipe the enemies.
I didn't like how I was forced to only pick one upgrade even though I had plenty of soul coins left, it was if it was forcing me to sacrifice as early as possible. I think it would be better to be able to upgrade multiple things if you have the coin for it.
Really well done, with lots of fun ideas. Good job!