Sure thing -- I'm using Firefox on Fedora Linux with NVIDIA graphics on a 4K display. It does seem to be related to screen resolution since the game behaves normally when on the page and only begins to misbehave when fullscreen. I'd try the download version but Itch.io says it's been quarantined. :(
Also forgot to mention, but the mouse cursor is glitchy too; it's the staticky rectangle in the screenshot.
