A set of custom interiors, based on Pikmin 2's different cave themes.
NOTE: Imperium's "night vision" setting was used in many of the below images to give a better view of the interiors. They are much darker where there aren't lights than it appears in these images.
Sandy floors and concrete walls are the aesthetics of this interior.
Its lights are Glowcap mushrooms.
This interior is modeled after a garden; rows of stones and twigs line the edges, with the occasional pond of water, or sand pile with a spade and pale.
It features an invisible light source above the false sky. Maybe it's a terrarium?
Uncanny metal structures tower over a deep abyss below. Be careful not to jump off!
LEDs called Glowstems are the main source of light.
A winter wonderland! Some tiles have tall plateaus, while others have one or more tree stumps, all covered in snow.
Also features Glowcap mushrooms.
Features mostly identical tiles to Snow, but as the name implies, it's themed like a classic dirt cave. It has the occasional clearing or grass patch, with light shining down from above.
Much like Snow, has Glowcap mushrooms for lights.
This interior is lined with sandy tiles, and has pools of water. It also has smaller "Pipe" theme tiles, with dark soil and rusted pipes.
It has Glowcap mushrooms growing through the tiled floors for lighting.
Picks between three "enclosure" themes at round start: a child's bedroom with a hardwood floor and chalk drawings, a tatami mat room, or the Garden theme's enclosure, without the invisible ceiling lights.
The tiles are lined by toy wooden blocks, and main entrance features the memorable toy train track tile. Some tiles have xylophones, tambourines, or rings of rainbow blocks.
Dangling light bulbs suspended by rope are the light source.
Instead of doors, these interiors have giant geysers. They may be familiar if you've played Pikmoons (or Pikmin 2, of course).
These geysers can be interacted with like a normal door, or if you're in a hurry, you can just run/jump into them to be whisked away to the surface.

Some areas you can normally access by throwing Pikmin in Pikmin 2 instead have a ladder to climb.
If you remember a location having treasure in the original game, scrap can likely spawn there!

In addition to treasure locations normally found in Pikmin 2, there are some other new locations that scrap can spawn in.
Keep your eyes peeled!
The Toy and Metal themes choose between a few background/enclosure variations each time you generate them.
Toy has wood, tatami, and grass enclosures, while metal has a snowy cylinder, dirt cylinder, or metal tiling background, though you'll only see the border walls if the moon's generation is sufficiently large, and you're near enough to them.
Each interior features Pikmin 2's elemental hazard props, which can be defeated with a shovel or other weapon.
It also features some other... more surprising hazards.
Geysers in the ground that spit out flames at regular intervals.

Identical to fire geysers, but they spew damaging, pressurized water instead.

Two wires that cause regular electrical arcs between them.
Can be defeated at either end.

A pipe that spews noxious red gas non-stop.

Sometimes, a giant boulder can fall from the sky. Run as soon as you hear it!

Similar to boulder traps, but the bomb takes a bit to explode. Again, run when you hear it!

Enemies can fall from the sky, too!
Don't worry, they're the less dangerous ones: Spore Lizards, Hoarding Bugs, Backwater Gunkfish, and Tulip Snakes are the only enemies that can spawn from these.

These sheets of paper are mostly not a hazard.
Unless a nearby dog hears them crinkle...

In addition to the spawn weights of whatever moon these interiors generate on, there are some enemies not normally found in interiors that spawn on the interior's end using itolib's EnemySpawner component.
Most interiors feature a 2% chance for Eyeless Dogs to spawn every two minutes.
More open interiors, specifically Metal, Garden, and Toy, instead have a 2% chance for either Eyeless Dogs, or Forest Keepers to spawn every two minutes.
These are kind of mean, but I just liked the idea of a giant chasing you through the Garden theme so much. Also, Pikmin 2 is mean anyways, so...
They have been mentioned, pictured, and/or described in each theme's section, but here they are listed out.
Flourescent mushrooms.

Light-emitting diodes of varying colors.
These interiors feature the all-new blue variant, completing the RGB set.

It's clearly not a real sky, but it does appear to rain light down.

These hanging bulbs are suspended via rope.
The bulb's wire coils around the rope up to the cieling.

Certain interiors feature plants, like the ones in the main Pikmoons mod.
Pictured below are some of them.
Large Figwort

Shoot

Margaret

Dandelions

Small Figwort and Small Dead Figwort

Fiddlehead

The power source for these interiors is the batteries from an Eternal Fuel Dynamo; rip them out to trigger facility shutdown.

This is the only scrap added by these interiors.
If you want more Pikmin-themed scrap to spawn inside, check out Pikmoons Scrap!
...do not exist yet. If I ever have access to the technology, I'd like to add them though!
The elemental hazards will only work properly if you have specifically LethalMin Nightly installed, not the main branch or library.
That version of LethalMin has better pathfinding for Pikmin leaving the interior. Without specifically the "Nightly" fork, every type of Pikmin will likely be immune to every hazard.
It is listed as deprecated at the time of this mod's first upload, but it should work fine for the most part.
If you want these interiors to spawn more frequently on a specific moon, you can add the namespace:key pair of your desired moon to the config of the interiors you want to spawn more.
If you don't know the namespace:key pair for your desired moon, simply boot up the game with the moon installed, and look for Dawnlib's debug line that says Registry 'Moons'.
Below where it says Registry 'Moons', every single moon you have installed is listed by their namespace:key pair.
Sometimes, on particularly large generations, the enclosure/border walls of an interior can block off part of the dungeon. This can only happen on Metal, Garden, and Toy themes. You shouldn't encounter this very often, though.
The only featured configs at the moment are Dawnlib's default-generated ones.
The interiors and all their dependencies should automatically install when using your mod manager of choice (Thunderstore, r2modman, Gale).
For manual installation, install BepInEx normally and drag and drop all .lethalbundles, .duskmod, and .dll files directly into a folder under BepInEx/plugins. This must also be done for dependencies.
Make sure you have all the required dependencies installed before launching the game!
(Bozoros and PlayZone are not dependencies, you MUST still download them, however, or else my dad who definitely works at Nintendo will ban you from all Nintendo products forever.)
All players are required to have this mod and all dependencies installed in order to be able to join the lobby at all.
If you encounter a game-breaking or very annoying bug, let me know in the Lethal Company Modding Discord thread for my mod, or the official Pikmoons Discord.
The thread can be found here.
I did not make Lethalmin. Any bugs relating to Pikmin behavior not directly relating to my mods should be reported to the Lethalmin thread on the lethal modding discord.
Extra thanks to pacoito for all the help making my mods. (He helped out quite a bit with many aspects of all of my projects, from general unity knowledge to writing custom scripts!)
pacoito for itolib, which I use for custom scrap, props, and most other script-based mechanics that aren't vanilla.
NoteBoxz for LethalMinNightly, and for making Lethalmin altogether.
JaySalty (on YouTube and Twitter) for providing assets and shaders used in this project.
Waffles for being so helpful in DMs, and for having such comprehensive documentation of Pikmin game sfx.
olimar12345 for being the GOAT and having the best Pikmin OST uploads on YouTube.
AudioKnight for StarlancerAIFix, which allows certain outside enemies to function inside normally.
IAmBatby for LethalLevelLoader, which allows these moons to exist at all.
Several other people on the Lethal Company Modding Discord, Pikmoons Discord, and social media for their support. :^)