Since modern browsers no longer support Adobe Flash Player, you will need specific tools to run a .swf file:
While the .swf file is a demo for an adult project, the title "Project Zero" is also the European name for the popular horror series. If you are looking for guides related to the main franchise: File: project-zero-awakening.swf ...
Flash files can carry security risks; always scan legacy files with antivirus software and run them in a sandboxed environment if possible. Since modern browsers no longer support Adobe Flash