Here is the full list of all 24 Sweet Dream Succubus - there are Nightmare Edition achievements.
Get all 3 endings.
Get killed by the succubus.
Get looped by a movie.
Get the succubus master ending.
Making the shady guy talk.
Get to credits screen.
Get a girlfriend
Solve her identity, her kind and her goal.
Beat the game in 3 loops
Discover her full name
Discover her second name
Get all events
Wear a condom!
Get the clinic event.
Skip a shower.
Getting the movie event.
Getting the church event
Discover her first name.
Getting the delivery event.
Starting a game loop.
Getting the hotel event
Getting the library event.
Getting the Jog event.
Starting a new game for the first time.