Here is the full list of all 37 Thousand Threads achievements.
Get the mailbag.
Open a piece of mail.
Deliver a piece of mail.
Deliver a piece of mail without opening it.
Deliver all the mail.
Help someone in need.
Complete a job.
Complete 20 jobs.
Complete 40 jobs.
Craft or upgrade an item.
Get all the Crafting Guides and upgrade all possible items.
Find an Artifact.
Find all the Artifacts.
Find a Fossil.
Find all the Fossils.
Open all chests.
Visit every region.
Fill in every segment of the map.
Learn everyone's name and what they look like.
Donate to save a life.
Donate to save 25 lives.
Donate to save 100 lives.
Take one animal skin.
Take 40 animal skins.
Take 160 animal skins.
Take one plant or fungus.
Take 100 plants or fungi.
Take 400 plants or fungi.
Take 10 stones.
Take 300 stones.
Take 1200 stones.