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