Here is the full list of all 27 Yomawari: Night Alone achievements.
Collected all items
Collected all collectable items for your room
Completed the puzzle
Completed the radio
Kidnapped by Mr. Yomawari
Collected all usable items
Picked up a trophy
Talked to Sis a total of 12 times
Found the Tsuchinoko
Cleared Chapter 7
Cleared Chapter 6
Played a total of 50 hours
Cleared Chapter 5
Picked up the Big Bell
Cleared Chapter 4
Made an offering to Jizo Statues a total of 50 times
Cleared Chapter 3
Opened Garbage Bags a total of 20 times
Stayed home for a total of 15 minutes
Suffered a Game Over a total of 30 times
Fed a cat
Kicked the can a total of 50 times
Hid a total of 50 times
Played a total of 10 minutes without the flashlight on
Cleared Chapter 2
Cleared Chapter 1
Cleared the opening