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