Newly Made
https://addons.mozilla.org/en-US/firefox/addon/gamer-but-blue/

Secret Gaming Essence poured into the computer

Here

https://addons.mozilla.org/en-US/firefox/addon/gamer-but-blue/

Yeah the URL text is by far the largest issue with the theme. I've tried several methods to remove it and none have worked :(

Edit: I think I've finally found a solution. If you check the description of the theme page it should be there