You need to run the .pkg file on a Mac that is compatible with macOS 10.12 so you can extract the actual installer app to the Applications folder. Then you need to create a bootable macOS USB installer. However, the macOS 10.12 installer has been broken for several years and needs a simple edit to one of the configuration files so it can be used to make a bootable macOS USB installer. I don't recall the exact item to edit. It would be better to use macOS 10.13 High Sierra.
How to create a bootable installer for macOS - Apple Support
Edit: I'm not sure how well a game will work in a VM. Does the VM at least allow the pass through of the GPU hardware drivers to allow hardware acceleration within the VM?