Interesting mechanic and narrative. I didn't quite get on board with the paranoia but maybe that's just the time contrainst not allowing to bring more of it. Would have been even more effective imo if all environment had been affected by the darkness equally - I could still see the, water, I think it was? My biggest comment would be the slidy movement, I don't find it too fitting. Good soudn design though, the increase with growing darkness was cool.