A Pokémon fangame, more centered on characters, with strategic combat (kinda like Pokémon Showdown) and no catching / farming. Whoops, looks like my current project!
Another project I'd like would be a boss rush, whose combats are rhythm games, and the bosses are generated by AI so they become progressively harder. The idea is: Furi, without the bullet-hell component.
Have you ever tried a music/videogame/movie/whatever, didn't like it, but wished you could like it?
Happened to me with Furi. I tried it three times within a year. I just can't understand bullet hells.