I'm afraid I don't know what's happening here. I can confirm it's not capitalisation of the track names -- I had that problem with one track during development, but I fixed it so it should all work on Linux. The browser version won't play audio until you've interacted with the page in some way, but once you've clicked on something it should start.

The only thing I can think of is that's something to do with the itch desktop app. Maybe try downloading the file directly from the web page rather than using the itch app?