Here is the full list of all 20 The MISSING: JJ Macfield and the Island of Memories achievements.
Escape from something scary.
Get run over by a train.
Fall off a bridge.
Escape danger.
Reach the top of the clock tower.
Complete the game.
Acquire every donut.
Find every Sleepy.
Read a hidden text from F.K. after finishing the game.
Read all of F.K.'s hidden texts after finishing the game.
Read all of the texts from the past.
Select Continue after the ending and start a new run.
Don't get too addicted to your phone.
Jump over that black thing!
Crane operation is dangerous work.
Find the first Sleepy.
Chat with F.K. for the first time.
Let the strange deer empower you.
First, you need to find Emily.
Awaken at the campground.