HOLY CRAP! Y'all weren't kidding, you really bumped up the difficulty. Truth be told, I spent about 20 minutes trying and I could not get past the first third of the level. There are two reasons to that I believe (three if you count me just being bad at the game).
#1: Enemies are very bullet spongey. It got to the point where I realized, especially when the red guys started showing up, that I could not kill them without sitting and focusing my fire directly on them for a few seconds. This caused me to give up trying to kill enemies entirely, and just focusing on dodging bullets, which, because I wasn't killing enemies, caused a feedback loop causing the game to get harder and harder. Maybe knocking down the HP for some of the enemies, especially the specials like the spiral and the machine gunner (no clue of their actual names, that's just what I'm getting from their mechanics), that would really help the issue of feeling like you can't kill them, and just focusing on trying to dodge bullets.
Speaking of dodging bullets, that brings me to #2: movement speed. I just could get the spaceship to react fast enough in order to dodge a lot of the bullets. Most bullet hell type shooters have VERY tight controls, almost mimicking the cursor exactly, so you can thread through tiny holes in bullet volleys. If you guys are trying to go for a different approach, totally great! But at times it feels as though I'm controlling the spaceship through a vat of honey. It just does not move fast enough for me to feel like I have complete control of the ship. One thing that could potentially remedy this issue and add an extra mechanic is a dash function that would cause your spaceship to go fast for a moment. It could even just be that when you hit the dash function, the ship snaps to exactly where your cursor is. You could have it on a cooldown or not, I just feel like that would really help! (Side note: I watched your videos on the boss battle [looks super cool btw, I really wish I could get to the point to try it] and it seems like you have a lot more responsive controls than I did. Maybe it's an issue with speed being tied to framerate or some other thing? You might want to look into that. I could even screencap my browser to show you what I mean if you think that would be helpful)
Okay I've been kinda critical about this update, but here are some positives: I LOVE how you tied the enemies to the music. You may have done this on the first one and I just didn't notice, but this is obvious and I am totally here for it! It not only is really fun in general to have everything go with the background music, but it's functional too! I found myself knowing to get prepared for the yellow sniper guy's attack by feeling the beats. DO MORE OF THIS THIS IS AWESOME. The boss fight looks really great too, and I'm excited to try it out! Also, the patch notes on the main screen are a great little touch. I'm looking forward to where this game goes!