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