Hello, I already have the first chapter of my game completed, and the script is also finished. I’d like to ask if I can participate by expanding it and creating a completely new chapter for my game, and then add it so I can showcase it. Thank you for your time

To clarify, you mean a second chapter to your already existing game project? 

As long as you start a completely new project file when the jam starts and it fits the theme, you can do that! We're pretty flexible. But it does need to be it's own entire new game project.