Probably too early to comment. I can start the game. I see the level and can move the [ghost-chasing-cat] with my cursor keys. But after ~3 seconds the level ends(?) and I get a blank screen with "Souls acquired: ☃x0". Doesn't matter whether I moved or where I am. I tried a few key-combos but didn't get to another level. Browser refresh restarts the game.
Fedora 33, x86_64, LXDE, Firefox 87.0