Full list of all 21 Warlock's Tower achievements worth 1,000 gamerscore. It takes around 1-2 hours to unlock all of the achievements on Xbox One.
Beat all Chambers stages
Finish the game
Talk to Keen's Kim
Reach the game's last world
Beat all Library stages
Talk to Möira's Rubick
Play a stage where there's a Fleye
Reach the game's fourth world
Beat all Warehouse stages
Talk to the Racketboy himself
Play a stage where there's a Slime
Reach the game's third world
Beat all Factory stages
Talk to Puzzle Depot's Todd Torial
Talk to Jess for the first time
Get the Magic Flag artifact
Reach the game's second world
Beat all Dungeon stages
Talk to Lenda do Herói's Hero
lay a stage where there's a Zombie
Talk to the Evil Warlock for the first time