I promised I'll check out your game, but this is too obtuse for me.
I get that there are two sine waves, and we have to get them to cancel out.
Prt-tip number one. If you are confused what the hell are you supposed to do: You have to make a wave that is the same as the wave you are given. You got four different wave shapes to do it. They do add up.
Pro-tip number two: Try increasing volume first. Without the volume, nothing you do will produce any change. The other buttons are not useless just because nothing happens when you click them - they do nothing if volume is at 0.
Still, I am plenty confused. What is note letter? Does it affect sine wave frequency? What is "Note number"? It also seems to change the frequency. And Volume doesn't affect just amplitude, it seems to add another sine waves to the mix? Also, what is "special"?
This game is a cool way of producing your own sounds. I really liked this deep monstrosity that made my headphones vibrate,