Here is the full list of all 13 Meowhalla achievements.
You dodged intimate relationship three times in a row.
You got yourself a slave.
You got Freya's ending.
You managed to end the game without killing any of Disir.
You got Inkeri's ending.
You managed to end the game without the battle against Hel army.
You managed to die in a visual novel. Good job!
You tried to run from Freya. Unsuccessfully.
You actually needed Erica's saliva to save someone.
You got Olga's ending.
You got Erica's ending.
You got Astrid's ending.
You managed to defend your honor against Freya.