The gameplay is surprisingly intuitive and and pleasant even without any visuals. I did feel that I started expecting more variety sooner than the game introduced. I got to a point where I seemed to be stuck (both directions produced very faint tones but I couldn't move forward in either direction without bumping into something). Perhaps the gameplay can be combined with other elements for a bit more guidance.
Thanks for the very helpful feedback! Yes, I've noticed that most players aren't getting quite as far as the main challenging gameplay element which is active echolocation (but this is a reasonable way in).
You've hit my nightmare bug - sorry about that! Particularly before you get the sonar there's not much you can do if the (extremely basic) pathfinding sends you into a wall. If you're curious - sounds like you got stuck somewhere in this map.