"Windows protected your PC" alert

This is a standard security feature put in place for anything that hasn't been downloaded directly from an app/games store.

Many of the games you are going to be testing are still in development, so they're not yet found in a public domain. This is why the message appears.

You can bypass this by checking your security software settings. However, if you're not happy to continue with a playtest that shows this message, we completely understand.