Really exciting and great audio. Just a couple of notes:
- On the controls screen, it might be good to put that "A" in a different font that has a bar; looked like a ^ to me and I was super confused about the controls at first.
- The top-right, top-left, bottom-right, and bottom-left zones are a shorter distance from screen edge than the horizontal ones, so the player has less response time. May be something to keep in mind for difficulty tuning.