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