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.
Finish the second chapter in normal mode.
Finish the first chapter in normal mode.
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.
Paint the picture correctly at the first try.
Manipulate the pictures to empty a frame.
Let Critter fly 3 times.
Catch Ma'Zaz in a trap.
Slide down the tricky stairs 3 times.
Try to climb the tricky stairs 3 times.
Finish the third chapter in hard mode.
Find out the machinists dirty little secret.
Convince Cornelius to lock himself up.
Join the Black Guards.
Make a penguin cocktail.
Scare Petra away.
Make the baby critter fly 3 times.
Finish the second chapter in hard mode.
Show Layla the stars.
Break the conveyor belt.
Click stuff 1000 times.
Distract the critter cook.
Disguise as a lamp 3 times.
Hit the penguin 3 times.
Finish the first chapter in hard mode.
Annoy the orc bounty huntress.
Point at stuff 1000 times
Open the captains little chest.
Look at all the outfits in the wardrobe.