Yep, that would be the DPI scaling issue I mention in the Install Instructions section, if you're on Windows. Not sure how to solve it on other platforms yet as my current main platform is Windows. Following the steps there should solve the problem if Windows is your OS, if not, changing your DPI scaling settings in your OS should solve it there.
Thanks a ton for doing a video on it though, glad you liked it! The confusion is more or less intended :) WarioWare was big on that.