Hey Daza!
Yeah I've been made aware of some issues with the itch app that I'm having trouble figuring out.
If you go to the main itch page (https://mixvio.itch.io/alcyone-the-last-city), scroll to the very bottom where it shows the demo downloads, and grab the win64 version there does that work? There also seems to be some weirdness in how itch's butler package manager is creating the zip files where it gives an error on unzip, but ignoring it seems to work for people hit by the bug.
I'm trying to figure out what the problem is, but this very much seems to be on itch's end and I'm unsure of what's going on there.