Good news, they've been working on adding C# support for a year or two now. I think it's still experimental, but from what I understand they already had a robust extension system that supported C/C++/Java/etc., so fitting C# in wasn't much of a stretch.
(it is only extension support -- not scripting -- but the extension system is such that it can be used for any game logic AFAIK)
(it is only extension support -- not scripting -- but the extension system is such that it can be used for any game logic AFAIK)