Here is the full list of all 22 Dreaming Sarah achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Finish the game.
Find the watch.
Find the juice box.
Find the dead cat.
Find the heart-shaped key.
Help the pianist.
Find the pill.
Find the bus card.
Find the shell necklace.
Shrink the eye.
Discover the ancient aliens.
Find the bullet.
Find the paint bucket.
Find the magnifying glass.
Find the ID card.
Find the glasses.
Find the compass.
Touch the moon bunny.
Find Blockhead.
Find the bag of seeds.
Find the hat.
Find the umbrella.