This game was amazing! I loved all the endings. The true end was my favorite true end from any game I played. It wasn't predictable and I don't know it was just AWESOME :)
Although as respectfully as possible I do kinda agree with "president mystery". I feel like if you could sprinkle some more hints though out the game.
Possible spoiler alert...
Ellen says that she's angry that "she" left her alone. and later it says "don't try to kill yourself". a possibility would be where Olivia was a real person like Ellen but got sick of it and killed herself . Oliva was replaced (kind of like the true end) so Ellen kills this thing to try and hide her sadness of Olivia's death. I do love your ending though. Or a different end could be that you just walked out the door/did your work/ didn't kill Olivia.
I do mean this in the nicest way possible, just as input if you plan on expanding, changing, or making a new game. Also I love the art style. One of my new favorite games and new favorite creator! Thanks for the AMAZING game! excited to see your other work!