Okay so far we have:

-High Casual
-Extremely distant future setting, post extinction event of the majority of civilization.
-Old technology is extremely rare and mysterious to the world's current inhabitants.
-The time before is hardly documented and almost treated as mythology
-Technology is akin to that of the early 18th century. The basic idea of firearms is common but definitely not perfected.
-Prior to the newly conquering empire, the land consisted of mostly massive tribe-like nations with their own customs and traditions. Things have been this way for several hundred years at this point.

What does everybody think?