Lunar Landscape

Lunar Landscape is the name of a level that has appeared in some personalized copies. It is a level with geography similar to the Moon except for a large castle made of cheese, likely referencing the old childhood belief that the Moon is made of cheese, which is said to look like a retexture of Peach's Castle. It has never been reported to replace a level, rather it replaces the broken star painting found on the Second Floor.

Geography
The level has Moon-like geography, with many craters and hills, bearing resemblance to the final boss area from the ROM Hack SM64: Last Impact. Most of the course uses the same texture as the Whomps, or a similar one. The castle in the center uses textures resembling blocks of cheese, and is commonly reported to have a stained-glass window featuring Mouser, implying it to be his castle.

Missions
There is currently only one reported mission, the first one, titled MAKE A MESS WITH MOUSER. There are few known details about this mission, but most people say it involves a boss fight against Mouser in the castle.

Speculation
The stage is believed to be an unused stage brought back by the Personalization A.I., likely being scrapped fairly early on. It is believed that it was replaced by The Starry-Night Skies, before being ultimately scrapped, as that is why the painting appears in place of the star painting. Some evidence in favor of this stage being scrapped early in the game's development is how the stage is reported to use the same texture as the Whomps. because the Whomps used different textures in earlier versions, it is possible that the texture was reused from Lunar Landscape after it was scrapped.