Here is the full list of all 22 Morkredd achievements worth 1,000 gamerscore. It takes around 6-8 hours to unlock all of the achievements on Xbox One.
Completed the game with a friend
Made noise with all the wind chimes
Disturbed all the legs
Found a mural in The Mountain
Found all the hidden murals
Squished all the worms
Started a co-op game
Completed the whole game without dying
Finished the game within 120 minutes
Completed the game alone
Completed The Meat without dying
Popped 50 pimples in The Meat
Found a mural in The Meat
Completed The Temple without dying
Found a mural in The Temple
Completed The Mountain without dying
Completed The River without dying
Found a mural in The River
Completed The Sewer without dying
Found a mural in The Sewer
Got killed by a shadow
Completed The Prologue without dying