Thanks for the kind words. Our composer wrote and recorded the music. He also put in the Wilhelm scream. I'm sure he'll be happy you recognized it. We were afraid the riddles were too hard, so I'm glad you found them challenging but solvable.
The riddles were spot on for me! I honestly only felt stumped for a minute or two. To be fair though, I think the number pad one is likely to trip people up if they don't have at least some musical background. Even so, the fact that the player has nowhere else to go means its pretty obvious to find the hint.