Do you mean why Unity adopted it, or why people generally use it for game dev? Unity uses C# for historical reasons - when Unity started, Mono was one of the f

Do you mean why Unity adopted it, or why people generally use it for game dev? Unity uses C# for historical reasons - when Unity started, Mono was one of the few options that fit their needs. Outside Unity, C# mindshare isn't that big I think. Java has been used a fair bit for Android games for obvious reasons, but game programmers are rarely Java fans.