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