No missable achievements (plus 22 unknown)
Sign in with Steam or Xbox to track your progress, and:
Find the umbrella.
Find the hat.
Find the bag of seeds.
Find the compass.
Find the magnifying glass.
Touch the moon bunny.
Find Blockhead.
Find the paint bucket.
Find the pill.
Find the glasses.
Find the ID card.
Find the shell necklace.
Find the bullet.
Find the dead cat.
Find the heart-shaped key.
Find the bus card.
Find the juice box.
Discover the ancient aliens.
Help the pianist.
Find the watch.
Shrink the eye.
Finish the game.