I had no idea there was a whole extended universe behind this game. I might give it a more thorough perusal when I have time. And I also didn't know that about manipulating Markus! That's actually pretty clever, like a hidden mechanic. As for making it more clear, I don't know, I'm not a game designer so I don't think I have the best ideas. I guess one way would be to highlight important gameplay related text in a different color, like red or yellow, but I don't know if whatever program you're using will let you do that. You could have Exit be just like, bluntly obvious, it would be believable because shes a smart character, and she has no reason to be vague to herself after all. But then again maybe she would do that, shes kind of a weirdo.
I'm happy I wasn't entirely wrong in my assessment of Markus. He definitely came off as a complete monster with no humanity in him at all. I hope he dies lmao. Anyway keep up the good work! It seem like you have so many ideas and characters already so I'm sure whatever you make next will be great!