This project uses gulp 3.9.1 to build, and currently does not work with Node 12+.
On windows you should install nvm-windows and tell it to use Node 11.15.0.
git clone https://github.com/mobmentality67/mobmentality67.github.io.git
cd mobmentality67.github.io.git
nvm install 11.15.0
nvm use 11.15.0
npm install
npm run gulp