Go to the releases page, download the latest release and extract it.
In VisualStudio 2017:
- Select the 'File->Open->Folder' menu item.
- In the "Select Folder" dialog choose the folder where you extracted the release.
- Select the "flappy-birds.exe" from the "Select Startup Item" list (the one with the play button).
- Click the "Select Startup Item" button to start the executable.
Instructions about how CMake works can be found in the CMakeLists.txt files.