I worked on the mine caves level in the last few days. The story will be kinda, you will go dow to fix something, the whole place will be much better lightid at this point. While you are doing jor job, there will be an explosion somewhere (probably up on the surface) and all the mine goes to emergency energy. That's why all the cave are go dark at this point.

 Still I'm trying to balance with the glowing crystals, and there will be vibrating big lights too. But the point is, to make this small part of the game a little bit slower, but more tense. You wont have weapons at this part, only a flaslight to find your way out through small platformer parts and theeen you'll find yourself front of an drone enemy without anything to fight against it... :)