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