Tried this mod with SA. Some moment became easier, some bullet became slower, but I haven't noticed a serious change in difficulty. For me it was strange the remove of the
noob strat on Sanae's first spell (when you could just dodge everything hugging the bottom of the screen). In my opinion, some Koishi's nonspells became harder, because the bullets became slower. And maybe Sanae's 3rd spell, Koishi's 2nd and 3rd spells should have slightly less bullets (and maybe the last phase of 9th spell could be slightly slower).
I liked the idea with additional
after midboss. Maybe in some games it could be a good idea if there could be an additional
at the middle of the boss (after 5th spell for example) like in Len'en.
Anyway, this project is interesting. I hope where will be more updates.