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 every Feather.
Collect everything.
Reforge every Legendary Weapon.
Complete every Side Quest.
Catch every Herptile.
Collect every Mask.
View every Lookout Point.
Catch every Fish.
Conquer every Fortress.
Light every beacon.
Say the perfect words in every Relationship.
Finish the Main 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.