I really love the mood music, it set the whole feels for me as I played. The music tone did add to the mystery of "what on earth am I supposed to do here?" but in a game puzzle way... so it's appropriate.
At first I had the impression that nothing was happening, until I decided to experiment with the other buttons on the lower part of the screen. Then I figured the issue I had... my laptop's screen was too small to see everything, so I was probably missing out on some visual cue or clue.
Congrats on the game's release!