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