"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.
Not sure how to playtest? We've made some example videos just for you here. You can use them as inspiration for your participations!
Please let us know at help@playtestcloud.com if you have any further questions about this.