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