I'm unfortunately unable to play past the angel boss fight. I'm just not able to not get hit by and also hit the angel at the same time. I guess I'm just genuinely bad at this type of boss fight. I've tried beating it for about 4 hours at this point with no luck.
Damn... Have you tried lowering the difficulty to the lowest setting?
I've been considering adding more difficulty options, including a "story only" kinda thing where you can't actually game over. You're not the first person to have trouble against the Angel, sorry about that
Hmm... The way it works is that the lowest your HP is, the quicker it regenerates. This effect is even stronger the lower the difficulty is. If you're still up for trying, I would recommend fully focusing on evasion, without attacking, whenever your heart becomes white (1 HP left) or even red (2 HP left). This will make it easier to regenerate, and you'll be able to observe the patterns as well (In fact, you could even spend a try or two just observing and learning, without the extra mental load of aiming and shooting)! Then, switch back to attacking once your heart has regenerated enough / during an easy pattern.
This is the best I've got currently, short of sharing a save file past the Angel fight and a video to catch up on story...!
I've tried it on the lower difficulty and have gotten to half health on the Angel, but from what I understand by reading the comments here there's a second phase after this first one. I think the main problem for me is there's just too much going on for me to process. I've enjoyed the game so far it's just this fight that has me completely stuck. I'm honestly fine with waiting for a potential update in the future with a "story only" difficulty. I'm just taking a break from trying to get past the angel right now, it feels like I'm just hitting a brick wall currently so I'll take a break for now and try again later.