Nice! Love the use of 3d sound here.
The only criticism I would give, is that there should be an introductory command telling you that you need to do *something* - don't say exactly what to do, just give a vague first goal - when I first played and followed the voice, and got killed at the tree, I actually had the impression this was the whole game! Only the title being so specific hinted that there was more to see - I then looked at the games page and saw there were spoilers instructions, so I launched the game again and looked around more. Just a vague starting text like "Perform The Ritual" or smth would work I think.
Or maybe no text at the start, but a hint like this on the death screen if you are killed without finding any other object of interest, so your first experience is kept the same as now, but it makes sure people know to try again.