Here is the full list of all 50 The Book of Unwritten Tales 2 achievements worth 1,000 gamerscore.
You've prevailed against evil
You've returned unscathed from the castle
You've turned Timmy back to normal
You've invoked the arch mage
You've beaten the Fear
You've chased off the spider in the Darkwood
You've obtained the ghost detecting device
You've won the battle, but not the war
You've obtained the Red Pirate's compass
You've obtained the Book of the Dead
You've won the Nim game without cheating
You've obtained the Spark of Life
You've freed your team mates
You've fulfilled the oracle's wishes
You've found Rémi and learned more about Wilburs staff
You've rescued Ivo
You've helped the zombies with the slate production
You've brought back a friend
You've strengthened a friendship
You've disguised convincingly
You've restored the electricity
You've escaped despite the surprising twist
You've animated your golem
You've mixed the magic ink
You've asked the right math problem at the first go
You've built your own golem
You've received the key to the city gate
You've stolen the lamp and fled
You've sobered up Nate
You've mastered your first day of school
You've finished the headmaster's cleaning tasks
You've solved the time travel side-quest
You brought back the library
You've rid the school of kobolds
You've read all student files
You've escaped the Elfburrow
You've received the hat of the Master Fisher
You know that Ivo is pregnant
You've finished the tutorial
You've survived the fall
Be enlightened five times
Hit all the symbols in the Drunken Punch minigame
Illuminate the dark cave
Solve the tasks of all four gods
Issue all four laws
Free your leader and your noble steed
Beat the Red Pirate at poker
Let Nate wear the "special" outfit
Obtain the Igor outfit
Watch the entire end credits