red51 I had a really cool idea! Know how you have content in the game that is a mixture of Medieval and Modern? Well I think it would be really cool to have an option so that you can switch from Modern to Medieval gameplay.
For example, if Medieval mode is selected, all modern content isn't available, so that people can build a Medieval themed world, and if Modern mode is enabled, people can build a modern themed world. Of course, a default option is recommended as well to have both content(the default game). Perhaps adding in more medieval and modern textures, as well as objects for the occasion?
I think a good amount of people would be very happy with this option!