Here is the full list of all 34 The Book of Unwritten Tales: The Critter Chronicles achievements.
Finish the fifth chapter in normal mode.
Finish the fourth chapter in normal mode.
Finish the third chapter in normal mode.
Find out the machinists dirty little secret.
Finish the second chapter in normal mode.
Finish the first chapter in normal mode.
Make the baby critter fly 3 times.
Paint the picture correctly at the first try.
Finish the fifth chapter in hard mode.
Find the best disguise for Critter to enter the sanctuary.
Let Critter wear every available costume part simultaneously.
Finish the fourth chapter in hard mode.
Manipulate the pictures to empty a frame.
Catch Ma'Zaz in a trap.
Try to climb the tricky stairs 3 times.
Slide down the tricky stairs 3 times.
Let Critter fly 3 times.
Finish the third chapter in hard mode.
Join the Black Guards.
Make a penguin cocktail.
Convince Cornelius to lock himself up.
Scare Petra away.
Finish the second chapter in hard mode.
Show Layla the stars.
Break the conveyor belt.
Distract the critter cook.
Disguise as a lamp 3 times.
Hit the penguin 3 times.
Finish the first chapter in hard mode.
Click stuff 1000 times.
Annoy the orc bounty huntress.
Point at stuff 1000 times
Open the captains little chest.
Look at all the outfits in the wardrobe.