This is a PAL demo, so it's worth setting your monitor to 50Hz refresh rate if possible to see it as intended. Many monitors will sync to 50Hz even if they don'

This is a PAL demo, so it's worth setting your monitor to 50Hz refresh rate if possible to see it as intended. Many monitors will sync to 50Hz even if they don't report it in the EDID. On Linux you can attempt to use arbitrary modelines with xrandr.