Hello there! I appreciate the lengthy feedback!
This game was originally because of a couple joke ideas from friends about what a game could have (like an annoyingly large party of characters to control, and a really strange stat system), but as I started putting them together I found it interesting enough to keep working with the idea. That's also the reason for the similarity with the name Mighty No. 9; this was originally just a joke game but I got attached to it.
I do want to have there be emotional attachment and character development, so I was thinking of having a large dungeon where you start with one character and gain a new one on each floor after completing a sidequest or something pertaining to them. Interacting with each character this way would help to build the player's relationship with each character that you come across, I think. The current roadblock I'm having is giving a motive for the starting character to be progressing through the dungeon in the first place, as well as why the other characters decide to join you rather than compete for whatever's at the end.
Having sacrifice be the centerpiece isn't a bad idea, and it may be fitting for how things go at the end of the game, but I want to focus on the accumulation and building up of the party and intercharacter relationships that are fostered. There will certainly be dramatic moments (especially considering certain character backstories and encounters I want to include), but I don't want to force many uncomfortable choices. I'd rather keep the characters and have more encounters and interactions that make the player appreciate them. Keeping the players interest on such a large cast is an interesting challenge that I'm hoping to somehow maintain throughout the game.
The reason it lags (outside of the start when it has to deal with loading that many characters onto the screen) is because I originally had every battle animation play on each affected character, and I found the result when I tested it funny enough to just leave that way. It's a simple fix that will be corrected in future releases. Elsewise, the combat is fairly repetitive and taxing in its current state.
I'm currently thinking of having each character have a few skills, but rather than going through each one in the current turn-based fashion, you pick one character to use a skill (or maybe just pick which character should act), and the enemy responds to it. It's sort of like a pacifist run of Undertale in that way, where you pick actions and try to get through the situation, except each character is set in what they can do each time, but there's a lot of options when looking across the whole cast. It'd be a way of representing conflict that allows for encounters with things that aren't monstrous in nature. I'm rather open to looking at other concepts for the gameplay system though.
I'll have a look at the Player vs. Protagonist relationship; thanks for recommending it!
Thank you again for your feedback, and I hope you enjoy what this game becomes!