This is a neat game but it just wasn't jiving with me. The panning of the sounds was a bit confusing for me (no difference between in front and behind is a bit annoying), and not being able to tell when I was walking as opposed to bumping into a wall was confusing as well. The sonar helps, but still leaves me unsure at times where to go. The monsters are also quite hard for me to predict and dodge. Because of this, I found myself madly running around a lot, and wasn't really able to finish the game.
The sounds are interesting. Some are very harsh and gave me a bit of a headache, though the pings for the sonar and finding the nodes fit really well. The footsteps and the node hum though don't fit that well for me.
My suggestions would be to change the sound of the node hum to something a little less harsh, and perhaps having an audible indicator for when you bumped into a wall.