Unable to adjust the screen resolution of a virtual machine created in ggRock above the default of 800x600.
Install the virtio graphics driver manually.
Ensure you have a recent snapshot of your system/games images before proceeding in order to ensure you are able to easily revert the change should any issue arise.
Download the latest virtio graphics driver from https://docs.fedoraproject.org/en-US/quick-docs/creating-windows-virtual-machines-using-virtio-drivers/index.html
Mount the ISO image inside of the virtual machine.
Modify the "Microsoft Basic Display Adapter" entry in the Device Manager snap-in, pointing it to use the qxlod\w10 folder in the ISO to force it to load the virtio driver.
Reboot and observe the screen resolution may now be adjusted.
It is advised that you not install all of the drivers, just the graphics driver itself.
This may have an adverse affect on the booting of physical systems from the system image/games image pair you have modified with the virtio driver. Before proceeding with any other modifications or snapshots it is suggested that you test all physical system types that use your system image to ensure there is no negative impact.