I think an architectural game should focus on the collaborative creation of buildings and structures. The rules should support planning and implementation, as well as the distribution of tasks among the players. An architectural game, finally, should give particular importance to the living beings that will “use” that building or structure. In short, I imagine a game that starts from an idea, puts it into practice and makes it available for the narration of a building. I don’t know if I’m being clear, I’m thinking out loud.
It sounds a bit too restrictive.
What i liked about the Invisible Cities series is the fact that these cities and building Calvino described weren't created through an architectural logical process, but were much more influenced by the passing of time, by the love of men for a dream, by our obsession for self-perfection, by the vertiginous idea of death etc...
In my understanding, an architectural game is more symply a game in which players experiment with and challenge the principles of architectures; just like what Calvino presented us with in his book: cities which challenged our preconceived ideas of why and how a city should be built.