Hey! Thanks so much for playing and giving feedback on the game. I think it's a really good idea to have the demon tell you the controls the first time instead of after. It seems like a tutorial would have been good to have! And also apologies on the lighting, I agree that it is both too dark and too light at the same time. We tried to provide a brightness setting to compensate for the overly dark areas, especially on the stairs. The material/shader on them seemed determined to be dark.
If you're curious, the monsters are meant to be passengers from the train your were on, so the descriptions are what the player remembers about them before they died. You get a journal entry by creeping behind the monsters, and that is what triggers the light under the monster.
The game is ultimately meant (although it doesn't do well at telling you) to be a puzzle game, where you connect the hints with the passenger descriptions. So the description of the person who wears great jackets that the player envies matches the hint for 'can only think of green' because of being green with envy. They may have been a bit too subtle :P.
Anyways, thanks again for taking the time to play!