Hmm... were you trying to download it using the itch.io Launcher application? As far as I know, for games to be downloadable with the launcher, the developer needs to tell itch.io what operating system each downloadable file is compatible with. Since I don't see a little Windows symbol on the game's itch.io page next to the file size of "Morfosi_Windows_1.2.0.zip", it doesn't seem like UniDot has done that yet, so it will need to be downloaded manually from a browser.