Ah, if the intent is for it to always be fullscreen, in the Itch project settings, you can set Embed options to “Click to launch in fullscreen” to enforce that behaviour.
Also, I’ve had a few framerate-dependent issues with various games during the jam on my 240hz display, and I think yours is another - at 240hz it’s very fast and slidy, if I drop to 60hz it’s much slower and easier to control. Think some deltatime issues are at play.