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