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