Here is the full list of all 12 Hidden Shelter achievements.
Answer correctly every question about the paintings.
Find 10 Teddy Bears.
Listen to the podcast
Open the room with flowers
Do the statue puzzle
Run from the creature the first time
Finish the game
Finish the game, unlocking the secret ending
Open the room with hanging bodies
Find the lab
Talk about the book Songs of Erysdar
Stand still for one minute in front of the scientist's wife grave.