What I've heard about Windows 10 with Galactic Civilizations III

"Will this game work in Windows 10? If not, are there any plans to make it compatible?"

James R. Wharton answered:

"No, not officially, because the drivers are still in flux. You may get it to work but any Windows updates may break the game.. Yes, the developers have said that when Win10 finishes its beta testing they will optimize the game for it."