Here is the full list of all 35 Runespell: Overture achievements.
Finish the game
Defeat Gullveig
Active a Powercard 100 times
Discover all major questlines in the game
Defeat two Wardens stones
Obtain all powercards
Win 20 battles without leaving the game
Collect 10000 hacksilver in the game
Deal in total more than 10 000 points of damage
Win 10 battles without leaving the game
Survive Wyrd Sister's Time Stop
Recruit all allies
Win 7 battles without using any Powercards
Defeat Warghul
Win 5 battles without using any Powercards
Defeat Dethgar and Ragnar
Win 15 battles in a row
Win 10 battles in a row
Win 3 battles without using any Powercards
Open 5 Treasure boxes
Defeat Berendur twice
Active a Powercard 50 times
Deal in total more than 5000 points of damage
Win 5 battles in a row
Use 7 card combinations in one battle
Collect 1000 hacksilver in the game
Deal in total more than 1000 points of damage
Win against an opponent with only 1 HP left on player side
Active a Powercard 10 times
Collect 100 hacksilver in the game
Win 5 battles without leaving the game
Use 3 card combinations in one battle
Use 5 card combinations in one battle
Unlock all achievements
Play all battles once