Honestly if the game has a major shortcoming it's that there's all these sidequests to do and the potential to become so absurdly powerful but the challenge just kind of stops being present once you hit level ~40 so it all feels a bit superfluous. Could really use a few superbosses, or maybe a harder difficulty setting.
Maybe that could be if they ever do a HD-2D remake, or something along the lines of the FF7 Remake series. This game would work a lot better for that format I think