Full list of all 20 Open World Game: the Open World Game achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
100% Completion + 1%.
Read every Journal Entry.
Collect everything.
Complete every Side Quest.
Collect every Mask.
Collect every Feather.
Catch every Herptile.
Conquer every Fortress.
View every Lookout Point.
Say the perfect words in every Relationship.
Catch every Fish.
Light every beacon.
Reforge every Legendary Weapon.
Reach Lv 100.
Finish the Main Quest.
Visit every Fast Travel location.
Finish the Generalist Skill Tree.
Unlock every Skill.
Finish the Speed-Runner Skill Tree.
Finish the Completionist Skill Tree.