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