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