Here is the full list of all 31 The Forest of Doom achievements.
Find the ultimate ending in Hardcore mode
Find all the artwork in The Forest of Doom
Find all the painted canvas pieces to unlock alternative cover
Fight a feline foe
Wield a carrot as a deadly weapon
Ride a strange looking horse
Be fired upon by arrows in four different encounters
Eat a strange fruit
Find the ultimate ending in Free Read mode
Tame a flying beast with music
Kill a creature who hates 'bwight light'
Reveal the truth about an individual
Help two souls out but be duped each time
Find your new destiny
Use an aromatic bulb to ward off a night terror
Find the ultimate ending in Medium mode
Find the two halves of the dwarfish hammer
Get caught in an Ogre's tree trap
Bounce your way out of trouble
Win an arm-wrestling contest
Buy all of Yaztromo's items
Return a brass bell to its owner
Successfully use the Net of Entanglement
Fight a creature that has been darted
Escape Darkwood Forest!
Face a barrage of eggshell splinters
Fight the iconic Shapechanger!
Release an Earth Elemental on to the world
Be lucky in a 'Test your Luck' roll
Suffer at the hands of lycanthropy
Be unlucky in a 'Test your Luck' roll