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.
Let Critter wear every available costume part simultaneously.
Find the best disguise for Critter to enter the sanctuary.
Finish the fourth chapter in hard mode.
Paint the picture correctly at the first try.
Manipulate the pictures to empty a frame.
Catch Ma'Zaz in a trap.
Slide down the tricky stairs 3 times.
Let Critter fly 3 times.
Try to climb the tricky stairs 3 times.
Finish the third chapter in hard mode.
Find out the machinists dirty little secret.
Join the Black Guards.
Make a penguin cocktail.
Convince Cornelius to lock himself up.
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.
Distract the critter cook.
Disguise as a lamp 3 times.
Hit the penguin 3 times.
Point at stuff 1000 times
Finish the first chapter in hard mode.
Annoy the orc bounty huntress.
Click stuff 1000 times.
Open the captains little chest.
Look at all the outfits in the wardrobe.