I really liked the mood of the game, and the music and whispering really added to that. The core mechanic is simple, so despite there not very good instructions on what to do, it wasn't difficult to figure it out.
I would have liked the character to move a bit faster. I spent a lot of time just walking around; with the amount of backtracking required, it did get a bit tedious. I also got lost quite a few times -- it was reminiscent of trying to get through the Rock Tunnel in Pokemon Red/Blue without Flash. So perhaps a somewhat larger vision range would have been useful, even if the extension isn't as bright.
Overall, a pretty nice game, with good sound and graphics!