Echolocation, that coupled with the oppressing darkness really makes one feel as if they are a mere bat flitting wildly about the complex in search of keys and crystals. The fine shader work really exemplifies that I believe.
I'll admit, I am not the stoutest of heart, more then once when I came upon the creature did my adrenaline spike. It really is a wonder that one can create a piece of art as such that elicits that kind of visceral response in such a short time.
Ah, and of course I loved the voice recordings.
Excellent work.