I'm a sucker for puzzle games, even though I suck at them, and I think how sound was worked into the gameplay is a really strong application of the theme. The sparse graphics design works great, and for the most part the game is intuitive enough that it doesn't need text or other hints. I love how everything makes a sound, too.
There were a few parts that felt really unclear and I really struggled with them. I thought the colours in the pie puzzle lined up to sounds, but that doesn't seem the case, and I still have no idea how I got past the keyboard/locks puzzle. I almost got stuck at the second moving blocks puzzle because I didn't realize there were two puzzles in that room and you had to solve the first one (a pie puzzle) to get the voice to move blocks north.
I think one of the sounds was also granted twice? Not sure.
The ending was weirdly meta.
I'm not sure if it was deliberate, but despite being marked as a Windows build the downloadable version appears to just be a copy of the web version.