I like the lighting and the idea that your vision diminishes as you go further. I haven't found the gold orb yet, but I like that you sometimes have to take risks to find another point to restore the light.
A few tips:
You can't walk diagonally right now, you could think about implementing that.
When you walk in a really long, straight corridor, you can't really tell that you are still going forward, so maybe you could avoid long corridors, or give the ground or walls a little more texture. Although not too much, because I do like the clean look.