Just so you know, there's a slight issue with the resolution! I think it might be an issue of being sized differently on different screens. I had the same issue - it's an easy fix by changing the stretch mode in the project settings to canvas_items before exporting :D If you don't want to reimport the game, just add a warning telling people to zoom in or out on their browser so they can see the whole thing
About your game, it's very creative and cute :D super well done!