Here is the full list of all 17 MISSING: An Interactive Thriller - there are Episode One achievements.
Complete the hidden word puzzle
Click 500 times anywhere
Completed Chapter 1 of Episode 1
Completed Chapter 2 of Episode 1
Completed Chapter 3 of Episode 1
Completed Chapter 4 of Episode 1
Completed Chapter 5 of Episode 1
Completed Episode 1
Solve the block puzzle in less than 5 seconds
Find the batteries before you need them
Hit the fire trigger on the first try
Hit all quick time event circles
Do not spill any coffee
Fix all parts of the generator
Shut 20 doors or drawers
Complete all achievements
Get out of the first room without completing the mystery word puzzle