Played a few runs of the game. Video: https://files.catbox.moe/lmogeu.mp4
First off, fantastic spritework. It really shows you put a lot of love into it. The game has a solid base to construct on.
The game occupies a very small part of the screen for my pc, but during cutscenes it is bigger. Why does it work like that?
I believe you underuse your sprite assets with the exception of the robot enemies. I don't think I have seen any girl appearing twice on the screen. I feel you can get away by using them much, much more. Give your players a chance to see your characters for longer, there is little need to restrict yourself so heavily. It also allows you to use gameplay piece more freely.
The intro should be skippable.
Your game is almost borderline, but since there is nudity from time to time, it throws the possibility of being on youtube out of the window. I know that this would take a lot of work, but have you considered about also having safe sprites for the few moments where there is nudity? I mean an option that can be toggled on/off from a menu.
The attacks do way too little damage and I believe the modifier didn't work. I cheated the attack level for the second run and it felt just right for the regular enemies, bosses were still too hard to kill. Also the shots fly way into the distance hitting enemies outside of the screen (you can see that on the video when using the bomb). The bomb indicator didn't seem to work.
I have been seeing your posts in the /v/ threads, so I'm happy to finally be able to try this game out. I do recommend you to be in /agdg/ a bit more, I'm sure you will get people to talk to and share ideas there.