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.
Read every Journal Entry.
100% Completion + 1%.
Collect everything.
Reforge every Legendary Weapon.
View every Lookout Point.
Say the perfect words in every Relationship.
Collect every Mask.
Complete every Side Quest.
Collect every Feather.
Conquer every Fortress.
Catch every Herptile.
Catch every Fish.
Visit every Fast Travel location.
Reach Lv 100.
Light every beacon.
Finish the Generalist Skill Tree.
Unlock every Skill.
Finish the Main Quest.
Finish the Completionist Skill Tree.
Finish the Speed-Runner Skill Tree.