This is the unofficial list of all default ambiance files and what they are supposed to be.
I made it by carefully analyzing and comparing the official levels (also, the ogg files actually have titles and authors in them, and it was first discovered by egomassive).
Basically, read this if you want your levels to sound as if Nifflas made them himself.
Of course, you can still make your own custom ambiance files.
Note: When I say “combine”, I’m obviously referring to the second ambiance channel, aka “B Ambiance”.
1. Strong wind. The loudest one.
Put dust (both particles and generators) to do it justice.
Ambi1-4 and 8-9 work really well together. I explain that better in the “Ambi1 Transitions” section.
2. Howling wind. Cave transition for Ambi1.
Put a pinch of dust (particles) if outside.
3. Howling wind lite. Internal to Ambi2.
Can replace Ambi2 if the transition is short and connects two outside areas.
4. Windy cave. Internal to Ambi3.
It's also good for nested caves (aka “a cave in a cave”, especially when it has a different tileset than the first one) to make them sound deeper or more ominous, or you can also just use it to differentiate caves in general.
5. Strong breeze. The one from The Tutorial.
Good as a louder alternative to Ambi11 and 12.
6. Leaves in wind. For Forests/Woods/Lotsa trees or big plants.
You must use it even if all the trees are dead and when they are far in the background. Put it in the sky above the forest if Juni can reach it.
You can also make a “special” quieter place with Ambi12 instead, but it's rare.
7. Mountain top wind. The only ambiance that’s not in any of the official levels.
Luckily, it has a self-explanatory name.
8. Howling wind outside. An outside transition for Ambi1.
You don't necessarily need dust (particles), but it doesn't hurt.
9. Cave. Good for everything underground.
10. Desert wind. Simple as that.
11. Gentle breeze. The all-rounder.
Basically, this one and Ambi12 are the best last resorts (outside). They are both good for exteriors and cities and can be used in relation to height (Ambi12 on the ground, 11 in higher places).
Good for fake deserts, solid clouds, and calm empty skies. You can also put it in a dead forest if "reviving" it is possible (that would give it a more distinct feel).
12. Light breeze. Even quieter than Ambi11.
Fits really well in snowy areas and large meadows.
13. A lot of water/The sea. Four tiles of water and up.
14. Some water/Calm water. One to four tiles of water.
You can break this rule to make calm bodies of water of any size.
15. Distant waterfall. For waterfall tiles placed in the background.
Combine with Ambi13 if you put deadly water tiles at the end (Note: you will sacrifice the wind by doing so).
16. Waterfall. For waterfall tiles placed in front of Juni.
This time, if the waterfall ends with water tiles, you don't need to combine it with 13. That means you can put wind instead. You can also break the rules and use this one instead of 15 if you need Channel B real bad.
17. Rain. Use the corresponding objects. Secondary (like water).
18. Lava. For deadly lava/magma tiles.
Especially good for magma in caves. In that case, this ambiance alone is enough, but you can combine it with Ambi9 if you want.
19. Underwater. Good for everything underwater, especially a certain lab…
Put some bubbles and fish objects to enhance the atmosphere, unless it's an underwater desert…
20. The Machine’s signature buzzing sounds. For “menacing” electronics and Big Bad lairs. This and 21 are secondary (like water and rain). As in, they are not supposed to replace wind.
21. Distant Machine. When you are in a screen that leads to Ambi20.
22. “The fluffy knyttpicker’s Machine thoughts” (or something like that). I don't even need to tell you how to use this one...
Secrets and weird/silly stuff. Most effective when used in just one or two really well-hidden secrets containing funny and unexpected nonsense, purposely designed to break immersion in a good way. A must for intentionally badly hand-drawn secret endings…
Must be used alone. Don't combine with anything.
Ambi1 Transitions
Basically, Ambi2-4 act as a transition between Ambi1 and 9, and they are replaced with Ambi8 if the destination is not a cave. This is also the reason why the files were numbered this way: Ambi1 is the outside, 2 is the cave entrance, 3 is one screen deeper than the entrance, and 4 is two screens deeper (Ambi9 is the rest of the cave, after that). If the cave has Ambi4 in place of 9, you just need 2 and 3 to bridge the gap, of course.
Use Ambi3 alone for one-screen-long tunnels connecting outside areas (as in, the path is a cave but the destinations aren't).
The rules in this section only apply when one end of the path is Ambi1, otherwise you don't need any transitions.
See the attachment for some examples.
General rules and tips
-Remember, you have two channels. Still, it's not mandatory to use both.
-Always put ambiance in empty skies if you can reach them. It shouldn’t suddenly go silent for no reason.
-Don't be fooled by the 1 in Ambi1. It's the loudest ambiance, not the default one. You shouldn't fill up your level with it in a cheap way.
-If you are inside a cave or indoors but can still be exposed to the outside ambiance (through open windows or holes, for instance), you have to treat the screen as outdoors and either use the same ambiance or combine them (if the ambiance in question is Ambi1, use Ambi2 when the holes are tiny. Otherwise, use Ambi8). This rule can be broken, but it's up to you to decide when or why.
-If the whole sides of a “cave” are completely missing (as in, you only used layer 3, for example), the screen is not underground (unless the gradient is not a sky).