that means they're not supported on your platform (most likely linux)
I think the itch app should let us download any file we choose to run as we see fit, tho
like, I wanna download windows games to run on wine, why can't I do that easily?
I get that, but many of the games I'm coming across seem to be available for windows and I still can't download it. The button says "open page" rather than download. I can also download zips through the app, but they download as if they were a random zip and don't go into my "downloaded games' rather into just my computer's download folder.