Here is the full list of all 20 The Guest achievements.
Complete the valves puzzle in less than 20 movements.
Solve the batteries puzzle in just 2 movements.
Wait 8 hours and hit the button again.
Get to the end.
Be thankful twice.
Type the password in the computer.
Get into the secret room.
Write BENEFACTOR on the typing machine.
Locate the Team Gotham's headquarter.
Try lighting a cigarette.
Complete the music puzzle without failing.
Read all the newspapers.
Complete the dream maze scene withouth failing.
Call every single number on the phonebook.
Turn off all the lights.
Collect all possible objects.
Use the sign and don't be disturbed.
Listen to some music on the record player.
Try consuming the bath pills again.
Enter the toolbox password without combining the notes.