Here is the full list of all 16 SEASON: A letter to the future achievements.
Witness the end of a season.
Exit the Valley before the flood enters it.
Arrive at the Shrine.
Capture Tieng Valley in a moment.
Help Sophon pack the last of her things.
Begin your political education.
Encounter a stranger and have a pleasant interaction.
See the outside world before it's gone.
Completely customize a page in your journal.
A journey of a thousand seasons begins with a single step.
Find a hidden botanical voice.
Uncover some kind of secret romance.
Leave a mark on Tieng Valley.
Listen to your friend's weird but meaningful dream.
Play a herd of cows their favorite genre of music.
Follow a little kid on a bike tour of the valley.