Here is the full list of all 14 ALONE? achievements.
Find and Unlock Ending 4
Find and Collect the Car Keys
Read All Notes
Enter the Morgue
Enter the Sewer
Collect all Screws
Replace 3 Piano Keys
Return the Jesus Statue
Unlock the Safe
Find and Unlock Ending 3
Enter the Basement
Find and Unlock Ending 2
Find and Collect the Flashlight
Find and Unlock Ending 1