I'm not having the same issue - try from the website.
Shame it doesn't work from the itch.io app but it does appear to work via the website... maybe it is to do with the itch manifest json? *shrug* I've yet to package something for itch.io so I don't know how it works but I've had downloads fail before that were related to that (apparently).
Anyway, thanks for checking and getting back to me, I'll try out the game when I have a moment! All the best :)