If you downloaded this from a third-party site rather than the official developer platforms (like Patreon or Itch.io), it is always a good idea to scan the .zip file with updated antivirus software before opening it.
Since it is a .zip file, you need to right-click it and select "Extract All" or use a tool like 7-Zip/WinRAR. File: ProjektPassion-0.6-pc.zip ...
It is an adult-themed sci-fi visual novel developed by a creator known as Airis . If you downloaded this from a third-party site
Version 0.6 is an early-access build. The game has since progressed much further (recent versions are in the 0.14+ range). File: ProjektPassion-0.6-pc.zip ...
The "pc" tag means this specific file is formatted for Windows or Linux operating systems. How to use this file: