So what can you do on Planet Popstar??? uhhhh idk.
You can sleep here.
Also did I tell you Zero likes to invade it a lot? Go help him invade it again.
A long time ago, in a galaxy far far away.... some girl named Cirno would decide "you know what? Fuck it I'm going to have my own planet!" and asked Galactic Nova to make her a planet with a bunch of idiots on it. And then she called it "Cirno Planet" after herself. Problem was she didn't know where it was because she never asked where it should be. Nobody for certain the true age of Planet Popstar. But from Ganondorf's account, this place is at least 66002000 years old. Eventually Dedede would become the first king after the citizens asked him to clobber that there Kirby.