Here is the full list of all 9 Hinterland achievements.
You did it! You won!
Attain level 4
Attain level 8
Attain level 12
Win without ever having anyone join party. (Req:Long, HC/Difficult, Raiders)
Win without any townspeople or party members dying. (Req:Long, HC/Difficult, Raiders)
Win without Lord Dying (Hardcore). (Req:Long, Raiders)
Defeat a monster more than 5 levels higher than Lord. (Req:Long, HC/Difficult, Raiders)
Win without fulfilling a request. (Req:Long, HC/Difficult, Raiders)