Thank you for the kind words and telling what you think about this game; I'm glad you liked it :D
I could easily put a window on those dark tunnels you mentioned, but I made them pitch black on purpose as an artistic way of telling that "sometimes you have no idea where you're going, but you still move on." to reflect our protagonist's situation in the abandoned factory: She has no idea where she is and what awaits her, but she keeps on going!