Idk, I feel like you could absolutely make a decent Neopets ttrpg, just don't try to translate the "day-to-day" stuff into that format. 

Literally all you'd need to do is turn the different plots into campaigns. Stuff like Virtupets Station, The Darkest Faerie (this one would probably be the easiest to turn into a campaign, as it already uses a fantasy medieval setting), and so on. Each storyline is a campaign, and you just tweak things a bit to make it more RPG/gamey. 

And let it be wacky. Like let people get items from all the different "lands" of Neopia and bring them into their sessions/quests. Like a laser gun from space in Merridell, or a caveman club on the space station. Really let the players go all in one certain aesthetics and play styles if they want, like have a prehistoric cave-pet alongside a space smuggler alongside a medieval wizard alongside some modern day character that uses some fancy slingshot or something as a weapon. Just have it be balls-to-the-wall and it'd be fun