Here is my game:https://itch.io/jam/gmtk-2019/rate/461185
Im not a sound geek but I have had 10 years of piano and 1 year of singing lessons. Pico 8 has limited but surprisingly nice sound. You get 4 chromatic scales and I typically make the noise I want with my mouth using a pitch monitor and a keyboard to try out pitches. Finally I used the resulting waves to map out the notes in the pico 8 sound editor.