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