Here is the full list of all 32 Röki achievements.
Acquire all other badges
Complete the game
Say everything that needs to be said
Open the gate to the tower
Find all of the castle explorer's notes
Get to know the castle's inhabitants
Solve the sundial puzzle
Find all the Guardian banners in the castle
Solve the dining hall puzzle
Complete Chapter 2
Insult Shroomi
See beyond the veil
Awaken Jötunúlfur
Find all of the petrified Trollbrothers
Awaken Jötunbjørn
Have Fossegrim charm an instrument
Examine 50 unique backpack items
Escape from the waterlogged caves
Open all of the Rootways
Complete Chapter 1
Help a troll
Rescue the Great Mother Tree
Summon a Tomte
Create a new path in the church
Activate the ice altar
Explore off the beaten track
Get to know the mill Tomte
Spin the top 5 times
Return Trollhilde's gold
Read every gravestone
Escort Lars to the outhouse
Successfully combine two items