Here is the full list of all 27 Dreamwalker: Never Fall Asleep achievements.
Release Sandra from the Nightmare.
Finish any Hidden Object Puzzle in less than 30 seconds.
Record the murderer's confession.
Get to Allan's atelier.
Find the hard evidence.
Escape the prison cell.
Break into the mayor's cabinet.
Read all the notes placed throughout the game.
Find the book about the Nightmare.
Save Hellen from the car wreckage.
Escape the carriage.
Get into the Tower.
Find Sandra's diary.
Finish three Minigames in a row without skipping.
Confront Sandra's trauma.
Complete any Hidden Object Puzzle without using a hint.
Find 3 Hidden Objects in 3 seconds.
Find your first Dreamer's Sheep.
Finish a Minigame in less than 1 minute.
Find 16 Dreamer's Sheep.
Find 32 Dreamer's Sheep.
Finish all Minigames without skipping.
Complete 3 Hidden Object Puzzles with no more than 5 mistakes in each one.
Complete all Hidden Object Puzzles without using a hint.
Watch all the cutscenes from the first hour of the game.
Finish all Meditation Minigames without skipping.
Collect all Postcards and Stamps.