What is in the "Way of Gold and Steel" which makes it interesting?

Main reason is the unusual gameplay style — combination of a real-time strategy (RTS) and a roguelike. As you know, in a typical RTS you issue global orders — basically what should be built and how to advance through the technology trees. It is different here. You control your character like you normally would do in a roguelike. Also you issue orders to your followers verbally, participate in fights, you have inventory and equipment. As a result we've got a mix of genres: real-time strategy and a dungeon crawler, two in one.