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.
Defeat OU.
Reunite the automata.
Free Anai-Sarava.
Have 20000 Morv.
Free the blackmarketeer.
Bring Hope into the world.
Free Anai-Raha.
Kill a boss with every playable character.
Complete 5 in-run events.
Upgrade The Book of Rea 15 times.
Shelter the stargazer.
Upgrade 25 times in the workshop.
Kill 100 enemies using hazards.
Rescue Mary.
Use 5 charms in the same dungeon run.
Free the runemender.
Have 3 runes equipped simultaneously.
Unlock all playable characters.
Kill 5000 enemies.
Kill 50 ferocious enemies.
Free Anai-Dya.
Unlock a family trait of three different Bergsons.
Upgrade The Book of Rea 5 times.
Save the wolf cub.
Gain each obelisk effect at least once.
Upgrade 10 times in the workshop.
Defeat the Spider King.
Free the shopkeeper.
Unlock a family trait.
Investigate the shrine of Rea.
Construct Ben's wine machine.
Complete 10 in-run events.
Upgrade 75 times in the workshop.
Unlock all family traits of a Bergson.
Unlock all family traits.
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.
Kill 250 ferocious enemies.
Finish a dungeon in co-op mode.
Revive 5 times in co-op mode.
Find 10 secrets.
Kill a boss without receiving damage.