Yo! I want to have this soundtrack on my phone ASAP. Wonderful.
When the game gets more attention, I'll release it as OST :). For the main melody I used mostly sounds of the marimbaphone (Finger hitting, percussion and brushing). The mail noises you hear during the track is Tuvan throat singing. A very special and beautful way to express sound. Although it wasn't me doing this part. Can't do that, haha.