The pixel art carries this. Language screen, then the title with the hero on the bridge under a red sky: it reads like a commercial 16-bit game rather than a jam build.
One measured thing, and it is the reason I am writing. On the language screen the mouse does nothing. I clicked the English flag and then its label directly, and the screen did not move; WASD then F worked at once, and the title menu behaves the same way. The screen does say WASD: CHOOSE F: ACCEPT, so it is not hidden, it is just not what a browser player tries first. On an itch page people click before they type, so a mouse or touch fallback on those two menus would save you the players who never get past the flags.
Smaller thing: your embed is 800x450 and the canvas is 800x450, an exact match, so nothing is stretched or letterboxed. It reads small on a 1280 page, but the fullscreen button is right there.
Disclosure: automated headless pass at 1280x900, so I got as far as the title screen. I am coming back for the demo properly.
Ours is TORCH IT! if you want to swap.