How to beat Final Boss.
Hang out at the top of the screen during ghost reappearing. Count to 8 as the ghost lady reappears again and again. At 8 (the last two she is invisible) start to move down, moving towards her if you can, and strike as you are going down. If you strike too early you will miss her. Always try to go under the laser, not over. Lasers kill you in one hit. You will die trying to beat this boss, just accept it.
When trying to hit her after/during laser keep your body far away from her. Your ghost attack hits very far from you, further than your normal attack. Only go very slightly in towards Lady from the center of the screen - seriously, use it from afar. The hitbox is terrible up close.
Unless you are right close to Lady, if you miss with the attack it is because you mistimed it. She is vulnerable a split second after firing laser begins and for a little teeny bit after. Normally if you miss once, don't try to attack again. The exception is if you miss because you attacked too early before she was vulnerable, in this case you can attack again and hit her.
After you hurt her immediately always go to the bottom, bottom, of the screen. If you don't you might instantly get hit with the ceiling lasers. If she starts doing ghost reappearing, go back to the top of the screen and count. If lasers from ceiling come, there is usually about 9 rounds of them. If you have a dark screen that's hard to see during this fight, like me, stay near the middle of the screen during the ceiling laser dodging. Keep your eye the entire time on the very top edge of the screen, if they appear above you or beside you make sure to run away instantly. If they don't appear above you then don't move around, unless you are just tapping left and right really fast.
If she does hand attack try to dodge them unless you can get them in front of you *while they are far away*. Primarily avoid them by dodging, use attack at the same time. Only don't focus on dodging if, like I said, you can attack them while they are far away. I find it easiest to stay at the bottom of the screen, kill them instantly if they appear down there, if you hear them spawn up top then get ready to dodge them and keep both directions they could come from in mind at once. Remember they go in a straight line from where they spawn to where you were when they started moving. Don't be afraid to fly around the middle in little arcs to dodge around them if you are at the bottom and you know they spawned up top. There is always 4 hands and then she comes back. Hitting the hands doesn't hurt her.
You can only hurt her during laser. One laser kills you but you instantly respawn so keep going. 3 hits from the ceiling or the hands instantly kills you. If you get hit by ceiling or hands and she pulls you into her then you instantly die. It's very easy to avoid getting pulled in.
If you haven't hit her more than 5 times but you have been hit by 2 ceiling lasers or hands then just die and try again. If you get hit by ceiling lasers or hands before you have hurt her 3 times then die or try again.
The first thing to get down is always dodging lasers by timing her appearance. Again, stay at the top, wait for two appearance timings after she stops appearing, then move down and try to hit her while always holding down until you get past laser. If you mess up the laser timing still then you are not going to beat her.
She might be easier if you have grinded or farmed but the game gives you very little orbs I find so I had basically nothing upgraded. I don't know if it gets easier if you farmed.
For beating this stupid boss you get a terrible ending, just like Xenotake.
It's only so bad because the rest of the game is so good. Why doesn't this guy have a patreon.