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