Here is the full list of all 33 Blankspace achievements.
Solved your first puzzle
Freed yourself from chains
Combined your first item
It's not for everyone
Aren't you feeling epic?
Found a NoBread logo
Found all NoBread logos
It's not cheating, it's having a good memory
Opened the 1st door
Opened the 2nd door
Opened the 3rd door
Opened the 4th door
Opened the 5th door
Unlocked the 6th door
Is it really the last one?
Maxed out affection points with Beryl
Maxed out doom points for Chris
Found every item in a single playthrough
Suggested every single panties option
Did you really check every single candle?
Unlocked the True Ending
Unlocked the Good Ending
Unlocked the Lost Ending
Unlocked the Sad Ending
Unlocked the Bad Ending
Unlocked the Dead Ending
Unlocked the Secret Ending
Got all puzzles right on the first try
Solved all 'Spot the differences' puzzles
Found the notebook
Because it sure isn't green!
Unlocked the whole gallery
Unlocked all main endings