Here is the full list of all 14 The First Tree achievements. It takes around 4-5 hours to unlock all of the achievements on Windows.
Uncover all secrets and discover a priceless treasure
Find your name again in a familiar place
Activate all of the obsidian rocks and unlock the way
Dig up your first item
Catch your first bunny
Find all 5 secret items
Find a secret item
Reveal the king of the rabbits!
Find your name
Collect all 150 stars
Finish the game
Uncover all main items in the game
Collect 100 stars
Collect 50 stars