Here is the full list of all 97 Slay the Princess achievements.
Successfully take the fight to a creature in its den
Unleash the power of pacifism on your foe
Take on a spirit and destroy it the only way you can.
Stuck in a dream without a stair to be seen
Bring the Wounded Wild to Her
Bring the Burned Grey to Her
Burn at the hands of a faded spirit
Slay an innocent
Have a voice ruin your happy ending
Some tears can never be mended
There are worse fates to suffer than a broken heart
You did it! You saved everyone!
Bring the Beast to Her
Free a creature while under extreme duress
Beget Strange Endings
Bring the Den to Her
Successfully flee from a creature in its den
Dodge a creature until you can dodge no longer
Strike the heart from the belly of the beast
Fool a predator by faking your own death
Freeze in front of a creature on your first meeting
Bring the Prisoner's head to Her
Free a prisoner
There's no going back now
Bring the Nightmare to Her
Let your terrors loose upon the world
When taken against your will, witness your enemy's freedom
Bring the Wraith to Her
When taken against your will, deal with your enemy the only way you can.
Fall for the rest of your life
Bring the Moment of Clarity to Her
See what hides behind her mask
Share a thorny prison
Leave a suspicious character in the basement
Bring the Witch to Her
It was in her nature
It was in your nature
Abandon her in a thorny prison
Slay the Princess, and make some enemies along the way
And at the end of that path is a cabin
Bring the Networked Wild to Her
Break the mirror without asking any questions.
Embrace your transformation
Directly attack a suspicious character
Take the bait from your foe
Fight your foe unarmed and go the distance
Lure an enemy to advantageous terrain and win
Cannot die cannot die cannot die
Bring the Adversary to Her
Bring the Eye of the Needle to Her
Free someone who doesn't want to be freed
Bring the Razor (Full) to Her
Master yourself and vanquish a sharp foe.
Bring the Razor's heart to Her
Allow a sharp foe to vanquish herself
Bring the Apotheosis to Her
Witness your better's ascension
Bring the Fury to Her
Slay your better
Bring the Tower to Her
Pledge your loyalty to your better.
Bring the Damsel to Her
Your love will set you free
Bring the Drowned Grey to Her
Drown at the hands of a faded spirit.
Dispatch a prisoner
Whatever it is, you'll face it together.
So have you become nothing once again
This is it
You don't know what you're doing
What can I do to make you stop?
Why have you come back?!
Return to your destined path, or face the consequences
Only new beginnings
Finish the Game. (The Good Ending doesn't count)
Slay the Princess
We Carve Meaning
Bring the Deconstructed Damsel to Her
All of this is you
Run out of questions
It's all she wanted
Bring the Spectre to Her
You've unraveled
Pick up a passenger and take her to her destination
Bring the Thorn to Her
You've withered
Work through some issues and learn to trust again.
Kiss her
Hand your power to a suspicious character.
Bring the Stranger to Her
You've grown
When everything is possible, nothing is.
You'll know it when you see it.
Bring the Prisoner to Her
Attempt to Out-Wait Your Destiny.
It's you
Become your own jailer