The same thing happened to me. I downloaded it from the Itch app and when I pressed launch it didn't work. I launched the files directly without the app and it worked fine. It seems like it doesn't launch with the Itch app?
That is particularly strange. It works for me when I tried it. Maybe it was a developer thing? I'll see what I can find out about it. Hopefully other people can find this solution here. Thank you guys.