Ah usually that’s because you loaded a character file or something when it asks for a world. It reads the character as if it’s a world, which just makes it place random stuff in the sky.
Also I’m not working on this anymore. Maybe, maybe, I’ll consider making my own original Terraria-like game in the future, maybe on Picotron instead of PICO-8, but I’ve added as much as I reasonably can to Terra and I’ve moved on to other projects.