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.
Reforge every Legendary Weapon.
Complete every Side Quest.
Conquer every Fortress.
View every Lookout Point.
Say the perfect words in every Relationship.
Collect every Feather.
Collect every Mask.
Catch every Fish.
Catch every Herptile.
Visit every Fast Travel location.
Light every beacon.
Reach Lv 100.
Finish the Main Quest.
Finish the Generalist Skill Tree.
Finish the Speed-Runner Skill Tree.
Unlock every Skill.
Finish the Completionist Skill Tree.