Blitzkrieg is a 2003 real-time tactics video game based on the events of World War II and is the first title in the Blitzkrieg series. The game was developed on an in-house game engine by the company Nival, primarily written in C and C++.
Since it is not compatible with modern game engines such as Unreal Engine or Unity, I believe it is mainly intended for educational purposes. However, it is possible that large language models could help update the codebase and create a simple framework for developing strategy games.