Cool I got into it!
It felt super hard at first because I wasn't playing in full screen, and you see way further in fullscreen.
I would slow the game by probably 10-20% overall, many time you simply don't have time to react to what's coming to you, which feels a bit unfair sometimes. In my game I added one variable that control the speed of EVERYTHING, player, projectile, enemies... and I would strongly recommend it, it was really helpful to tune the game so that it matches the average human response time if that makes sense. Here for example I was never really able to look at my health, you simply don't have time.
Also, it would need a bit of feedback when you get hit, it's not obvious when you get hit or not and overall I never knew in what shape I was, death came "as a surprise"