Here is the full list of all 45 Children of Morta achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Investigate the shrine of Rea.
Defeat the Spider King.
Free Anai-Dya.
Rescue Mary.
Free Anai-Raha.
Bring Hope into the world.
Free Anai-Sarava.
Defeat OU.
Save the wolf cub.
Shelter the stargazer.
Reunite the automata.
Construct Ben's wine machine.
Complete 5 in-run events.
Complete 10 in-run events.
Free the shopkeeper.
Free the runemender.
Free the blackmarketeer.
Upgrade 10 times in the workshop.
Upgrade 25 times in the workshop.
Upgrade 75 times in the workshop.
Upgrade The Book of Rea 5 times.
Upgrade The Book of Rea 15 times.
Unlock a family trait.
Unlock all family traits of a Bergson.
Unlock a family trait of three different Bergsons.
Unlock all family traits.
Unlock all playable characters.
Have 20000 Morv.
Bring back 15 souvenirs from the dungeons.
Find 20 journals.
Resolve 20 puzzle events.
Complete 10 challenge rooms.
Find 10 divine items in a single dungeon.
Have 3 runes equipped simultaneously.
Use 5 charms in the same dungeon run.
Gain each obelisk effect at least once.
Kill 100 enemies using hazards.
Kill 5000 enemies.
Kill 50 ferocious enemies.
Kill 250 ferocious enemies.
Finish a dungeon in co-op mode.
Revive 5 times in co-op mode.
Find 10 secrets.
Kill a boss with every playable character.
Kill a boss without receiving damage.