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