SpecFlowWeaponry is a project mainly written in C#, it's free.
Some awesome weapon-based action, which also demonstrates BDD using SpecFlow
Super cool weaponry based mayhem which also illustrates use of BDD with SpecFlow!
Also trying out Should.Fluent for assertions.
SpecFlow: http://www.specflow.org/
Should.Fluent: http://should.codeplex.com/