Here is the full list of all 20 At Winter's End achievements.
Start a game of hide-and-seek with some friends
Roll the dice and decide what to say
Find Olive and Sienna on the second day
Find Olive and Sienna on the third day
Find Olive and Sienna on the fourth day
Find Olive and Sienna on all days
Help Capybara find Rat
Use your creativity to help Flower manage its time
Use your empathy to help Flower manage its time
Use your wisdom to help Flower manage its time
Use your creativity to help Bird choose a new home
Use your empathy to help Bird choose a new home
Use your wisdom to help Bird choose a new home
Help Pond prepare for the changes of spring
Learn from your experiences and stand up to Winter
Finish the game
Ponder every interactable object in the woods
Find a single die face with three symbols on it
Replace all of the blank faces on your dice
Have a total of 13 or more symbols on a single die