Skylancer: I was able to get NOX to run completing the following:
Tested under Windows 7, 8.1, 10 x64 Platforms
*This is just an FYI for anyone experiencing issues with flickering or un-viewable videos and menus*

1. Locate NOX.exe from the GOG default installation directory
2. Right Click Modify - Compatibility Tab
a. Select 'Change Settings for All Users'
b. Change 'Run this in Compatibility Mode': Windows 98/ME
c. Reduced Color Mode: 16-bit
3. Apply and OK

Recommended as well is to disable Virtual Super Resolution (AMD) or Supersampling DSR (nVidia):
GOG NOX Support Portal - www.gog.com/support/nox

Mileage may vary but has worked for several friends and co-workers.