The engine is in C++, but the game itself is written in C# (and this is the actual part you'd called out earlier in this thread), and no it's not “just scripting on top of the the engine”, no more than writing a game engine in C++ is “scripting on top of the OS” your definition of what is scripting and whatnot is just off.
I'm describing how the engine is actually made... It's mostly written in C++ and C# is the application scripting layer.
If the whole thing was C# top to bottom I'd call it a C# engine.