Wait a moment after clicking the green flag for the composite sprite of your Melon Bread to appear. You will notice that my technical knowledge of programming is allowing this tech demo to be displayed, and if you are a Gunstar Heroes Existence Acknowledger, (is "Acknowledger" a word?) you will recognize it.
I guess that this is my April Fool's Day project. Clicking the "Don't just stand there!" button will make your Melon Bread look up and down and also open and close his mouth. Clicking the "Stand there!" button will make your Melon Bread freeze in place, which will allow you to use the sliders. The "jaw " slider adjusts the mouth. The "face" slider adjusts the looking angle of the face. The "turn" slider rotates your Melon Bread. Clicking the "Close your mouth!" button will make your Melon Bread look up and down, but without opening his mouth. Check this out: https://www.desmos.com/3d/afabbba1c9