This is almost always because the developer has not tagged their project files correctly. If you want to tell us here which projects you had an issue with, or report the games from the bottom of a page, we can go update the classifications.
Alright. Thanks Leaf! Sometimes the .zip files are labeled "windows" or "mac" that might help too.
There have been a few games I've found that just don't seem to work with the itch.io client. I'll start reporting them rather than complaining to the devs in the comments section.
You can also mention devs in the comments! Reports go to us, and we can update tags on files if necessary, but if there's something about the game that doesn't work then the dev will have to fix it. Generally getting the dev to test their game through the app is the best way to get stuff fixed.
