Here is the full list of all 26 Thea 2: The Shattering achievements worth 1,000 gamerscore.
Destroy 5 settlements
Have a character die in a group without food
Play for 500 turns
Reach lvl 20 on a character
Win a difficulty 5+ challenge without sustaining any damage
Craft 50 equipment items
Have only Goblin Wine as food in your party during 3 consecutive night turns
Have 20 different food types in a group's inventory
Win a challenge that autoresolve deemed to be unbeatable
Visit another biome
Complete all Theopedia terrain entries
Retreat from a difficulty 1 challenge
Complete Resources research tree
Complete Items research tree
Unlock all gods
Finish the main quest playing on hard difficulty
Start with two human children only and survive 100 turns
Craft The Other Ring using only Tier 5 materials
Finish the main quest and become allied with the Light
Finish the Divine Path quest with a chosen who started as a rat
Win without founding a village
Do not let your people consume meat or meat-containing meals for 50 turns
Travel 1000 tiles on sea
Eliminate all opponents before the Fight Phase begins
Recruit Captain Bear
Trade for 3000 worth of items using only food