Picosynth is controlled by drawing a waveform on the canvas that gets played back.
I recommend you run on your local console through splore as the web edition has issues. This also allows you to record clips and save them.
Picosynth works by filling up a buffer with copies of data from the canvas and outputting it to the speakers.
It also includes a fast-fourier transform to display frequencies and control the robot avatar.
Blobby drawing tool
Original prototype that became blobpaint.net
A surreal game used to explore rendering in pico-8.
Controlled via arrow keys