[pjmlp]

Not sure about Unity in particular, I would say that is already part of .NET given its linage, don't forget J++ was going to be the main language of what became .NET, had it not been for Sun's lawsuit.

Many of the Unity capabilities are built on top of Mono, and the reference implementation alongside Visual Studio has more capabilities still.

If you mean the game editor experience itself, yes the interactive development ideas are there, but so are they in any game engine reasonable modern worth using.