Have you checked your laptop manufacturer's support website to see if they have released a Windows 10 video driver? Windows could be using a generic driver that is for the correct video but has limited capabilities.
I have a Macbook Pro running Boot Camp. As far as I know, I'm using the latest Nvidia driver for my system...
Which model MacBook Pro? I ask because any MacBook Pro model before the Mid 2012 models does not officially support Windows 10. So, that could be a factor if you are using an older MBP.
Which macOS version? I ask because many times Apple does not support newer version of Windows with older versions of Bootcamp and the newest version of Bootcamp is basically only guaranteed to be in the most current version of the macOS (which effectively would be El Capitan, aka 10.11.x, although Sierra, aka 10.12.x, is officially being released today). So, if you are not running El Capitan, then you might want to consider upgrading to at least El Capitan (assuming it is still available in the App Store...Apple has an annoying habit of removing old versions from the App Store is you have not at least downloaded it once while it was the most current version of the macOS, which is why I download it even if I am not going to upgrade).
Assuming neither of the two previous items might be the issues, the thing to try is to reinstall/update the Windows support software (this is the software that essentially installed the Windows graphics driver for your particular MacBook Pro model). This article will provide guidance:https://support.apple.com/en-us/HT204923
And one last thought would be to try a virtual machine with Windows 10 in it. While it is generally better to use Bootcamp for things like playing Windows games on a Mac, virtual machine programs (especially Parallels) have gotten much better/faster at handling graphically intensive programs. And since the game is a 2006 game, it is not going to push a newer MBP's graphics system (assuming dedicated graphics which seems to be the case if it is nVidia) too hard. So, there is a good chance that an older game might run pretty well in a Windows 10 VM running inside of Parallels. You will still lose a little performance, but it might still be more than playable. And you would not have to reboot to play it.