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.
Help the pianist.
Finish the game.
Find the watch.
Find the juice box.
Shrink the eye.
Find the bullet.
Discover the ancient aliens.
Find the ID card.
Find the dead cat.
Find the heart-shaped key.
Find the glasses.
Find the bus card.
Touch the moon bunny.
Find the shell necklace.
Find Blockhead.
Find the pill.
Find the paint bucket.
Find the magnifying glass.
Find the compass.
Find the bag of seeds.
Find the umbrella.
Find the hat.