Lighting made the castle somewhat menacing, with its solely red lighting. Additionally, it made the place feel less empty. To balance the mood with visibility, I made sure to space out the braziers so they didn't make the area too bright. They create a pathway up the stairs and to the exit by highlighting areas of importance. Light can often be used as just a way to make sure the player can see what they're doing, but it is also important to make sure the light subtly hints to the player what the objective is.
Having the lights flicker instead of being constant added movement to an otherwise static scene, unlike outside where the trees create an illusion of life. While we certainly didn't customize any of the lights, unless I missed something, variation would have added a good bit of detail. Variations help hold up the curtain, it makes games feel less manufactured and more crafted. It usually takes away from a game to have one single asset that gets used over and over again. If I wanted to use dynamic shadows, I think that making the end crystals project over the floor would make the ending feel more grand.