Thank you very much! I'm not sure if I "consciously kept things mysterious" rather than just "stumbled into a confusing setup", but I'll take it :)
And my bad about the resolution! Somehow I set my mind to 100x100 at the start, and figured a fixed 800x800 would be more than big enough, and just left the full screen. Should've realised this won't do for any x720 screen of course. I'll be sure to fix it if/when I continue this project!