Cool game, but it doesn't work on Safari, Chrome, or Firefox on MacOS 10.14 Mohave. I worked out that it will work if the colorblind checkbox is checked, but I

Cool game, but it doesn't work on Safari, Chrome, or Firefox on MacOS 10.14 Mohave. I worked out that it will work if the colorblind checkbox is checked, but I had to clear the cookie to find that out. Problem with the emojis I guess, but there's no need to use emojis just to get a coloured block — you could do that with a couple of lines of CSS. It's good that you didn't use a JS framework, though given that the only changes to the page as the game progresses are updating the grid cells and a couple of bits of text, it would be pretty crazy if you did. Also, I was amused that the example gif is over half the total page weight. You could do a mini demo/practice level instead in much less.