This is a really cool looking game, especially for your first gamejam! There's always stuff that ends up not making it into the submission.
In terms of fitting the theme, the one light thing doesn't seem to really affect the gameplay all that much. You could have lit the entire map normally and the game would be mostly the same. I think ideally, the "only one" feature should be implemented such that if it were removed, the game wouldn't be the same any more.
Also, I didn't realise you could hide from the ghost in the hole, so I kept getting killed by the ghost.
Great job on your first jam, hope you had fun! :)
- Joe