But it doesn't seem to have it's source publicly available

I already know about this game, and I even mentioned it in the post

By in-game manual I meant a manual which built directly into the game and a main character could read it, not just a player who opened a PDF outside the game. And also usually those manuals are stylized, like in papers please (which I forgot to mention in the post btw) or like in Uncle Chop's rocket shop

Thanks for the notice, the .ml were seen suspicious to me earlier, especially when I saw the last thing I was supposed to write in the ancet field or whatever it was called

Okay thanks