Here is the full list of all 10 Eternal Threads achievements.
Read all letters in the house.
Listen to voicemails for all six housemates.
Save all six housemates while also resolving their personal issues.
Receive a final revelation.
Save all six housemates.
Witness every possible event across all the different timelines.
Watch all possible death scenes across all the possible time lines.
Watch all the housemates reveal their secrets.
Open all four locked doors in the house.
Save one housemate.