Technically OFF did it first back in 2008I didn’t like Undertale for reference but I remember back then people saying this did it first and better
Not sure if you're talking about this release specifically (vs. the Anodynes) or LISA: The First which isn't included. If my understanding is correct (as I haven't played it myself) LTF is more akin to Yume Nikki whereas Painful/Joyful are clearly Mother-likes. That said, you don't really need to know anything from LTF to "enjoy" Painful/Joyful (although I think it explains some of the deeper backstory for some of the characters which you can also surface out of a wiki).Will give the first one a try on Switch next month and go from there!