I've been playing this mod for a while now and have done my share of lurking here. Yet after once again grinding to a halt in the galactic era I noticed that the game starts to lose flavour there. Sure the trees are not finished there, but what I am missing is some sort of "gadget" to make the later ages more interesting. For example, loosely said, the development of the game can be somewhat condensed as: hunting / exploring -> expanding / early diplomacy / religion -> guilds / advanced governments and civics -> exploring oversea / more advance diplomacy -> air units / corporations -> spaceship -> ???. Once you finish the spaceship, the rest of the ages do not seem to give anything really interesting.
Having played since Civ 1, I know that in "Civ 2 Fantastic Worlds" a mod was added to add underwater cities. Since outer space cities seem to be hard (if not impossible) to implement, I was wondering if it would perhaps be possible to expand cities into deep sea. The buildings one could build in such underwater cities should of course be completely different, but no less interesting! Likewise, the sea component of the mod is slightly limited too. Stuff like "attrition" could be implemented for any wooden ship even into the renaissance age and more sea resources could be considered. To name a few examples: "Algae", "Corals", more types of sea fauna, etc. Underwater terrain and features could be a possibility too, such as underwater chasms or volcanoes.
I also noticed that compared to earlier ages, the world wonders in the later era's are few! Would love to see some more being added there

*cough* wonderjunkie *cough*
While I don't have any concrete ideas myself, I just wanted to put this out there!