So, I have to start off by saying that this is some really impressive mechanical and audio design. Since the whole game hinges on sound it was important that you nailed that, and you did! The echolocation was fantastic as well with the pulsating and breath mechanics. However, I found it extraordinarily difficult to figure out where I was supposed to be going and there wasn't any real sense of progression. Adding on top of that, there was very little respite for the tension the game is so amazing at building, because of this I became burnt out pretty quickly as there was never really a time set aside to calm down, collect yourself and enjoy the world. With a few tweaks the game could see some massive improvements in overall feel, communication and effectiveness, but as it is, it's still damn impressive!