Pico's world
Pico's world is an area in the remix world that the Pico's Bizarre Adventure series of games takes place in.
It is a world full of platformer levels, based on standard Scratch platformers; it's filled with different-colored elements that Pico must interact with, such as portals and lava. As with most places in the remix world, it is constantly changing, and the specific levels vary often. Sometimes, it's even been redecorated by a particular Scratch user, who wishes to make it more Christmassy.
Denizens
The Guardian of the Portal seems to live here, attempting to stop people from going through the portals to the next level.
Pico used to hang out and adventure in this world a lot, but over time stopped doing so. However, they brought Mecker to it when she expressed a wish to be part of a real game, and she stayed there for a while.