I'll give my impressions on this game:
1. At least for me, 30 fps doesn't seem smooth at all;
1b. With the game at 30 fps, you are probably going to have problems detecting collisions on small but fast bullets, as they can go through the player in a span of two frames;
1c. I've read somewhere that "you cannot change the game fps otherwise you'll need to modify the patterns too, which probably means you tied the ingame time to the fps. Does that mean you cannot change vsync on/off? What if I play the game on a higher refresh rate display and on fullscreen mode?;2. Everything hitbox seems too big, probably another result from running it at 30 fps;
3. The current stages are basically nonexistant, they even fail to fullfill the "filler" role because:
- The patterns are either too easy (even for Lunatic) and/or repeated over and over;
- The duration of stage portions before/after midboss are really, really short;
4. Don't know if the soundtrack is a placeholder - I'm assuming it isn't, since you linked it on the first post but I didn't opened it yet - but it's not fitting the stages/bosses at all;
5. The "ice spears" bullets on the first stage are almost impossible to read with this water background if I don't (almost literally) put my face on the screen;
6. The transitions from [menus > gameplay], [stage portion > boss] and [stage > next stage] are nonexistant too;
7. Might be a biased opinion, but every character seems to have the same movement speed, and it's damn slow;
I am extremely sorry to give you such negative feedback, but when everything said above sums up, I end up not enjoying the game in the slightest and basically rage quitting.
I'll give you credits for coming up with an original engine - I know it's not an easy task - but I honestly think you should work on polishing the game on said points. You came so far, so I think you can do it.