Lunar Lunar Moon

Not to be confused with Lunar Landscape

Lunar Lunar Moon is an anomalous level in Super Mario 64 that only appears in some personalized copies. Despite the Lunar inspiration, the outdoor Moon part of the level is fairly small and linear. The level has been known to feature an "air" meter similar to how health slowly declines while underwater in levels like Jolly Roger Bay or Wet Dry World. This forces the player to stay mostly in the indoor sections of the level.

Geography
Lunar Lunar Moon features two main parts. The rocky outdoor section of the level, and the more mechanical-inspired indoor parts of the level.

Indoors
The Indoor sections of Lunar Lunar Moon are entered via an airlock on the side of one of the mountains, and the indoor area is also where Mario enters the level. The indoor parts are described as "a blend of whirring mechanical parts and natural cave stone". The indoor sections of the level have mining equipment scattered throughout the area, along with a few spinning cogs found on the wall.

The Lunar Lunar Moon caves have an upstairs and downstairs section, with the upper level featuring many windows to the outdoors and more of a mechanical look, while the lower caves are less mechanic in appearance.

Most reports of star locations aren't accurate to other reports, but most universally say that there's a star at the end of the outdoor area.

Outdoors
The outdoor section of the level isn't an area where you can explore and find secrets, but acts more of like a linear styled level, akin to the Bowser stages in Mario 64. This, with the air meter in mind, makes the area much more difficult as you're forced to complete it on a time limit.

Rumors
People have rumored Lunar Lunar Moon to cause players to commit suicide, though no conclusive evidence really supports this being true. Much like Polybius, insane rumors were created for publicities sake. This could also be due to a lot of misinformation, as many people make fake reports.