General issue #1: Very heavy dependence on nanomaterials. When it comes to units needing strategic resources, let's compare some vanilla ones to nanomaterials:

Iron: Used for two unit lines: infantry (Swordsmen -> Longswordsmen) and ranged naval (Frigates).
Horses: Used for two unit lines: mounted (Horsemen/Chariot Archers -> Knights -> Cavalry) and anti-mounted (Lancers).
Nanomaterials: Used for nine unit lines: "mounted" (Railgun Armor -> GDRs), anti-"mounted" (Vertols, Hovertanks), siege (Mech Artillery, Crawlers), submarines (Cybersubs), carriers/support units (Nanohives, Nexus), paratroopers (XCOMs), fighters (Drone Fighters), bombers (Suborbital Bombers), giant bio thing (Bio-Titan).

This is in addition to needing nanomaterials for any of the megastructure wonders you want to build, which take six each, and there's five or six of those. (And of course for spaceship parts...) Because of how nanomaterials are gained, it's hard to build up a big enough supply sometimes without building/capturing many more cities than you would need otherwise. Maybe reduce the number of places they're needed, reduce how many are needed (take megastructures down to 3 or 4 apiece?), or make them easier to obtain. Running out of nanomaterials locks you out of way too many areas of the game right now, far more so than any other strategic resource.


General issue #2: An abundance of mutual-exclusivity in buildings. I understand your goal in going for different societal types by focusing on different elements, but it just becomes confusing very quickly and doesn't make a lot of sense logistically. Why should a genetics lab (which you would think would be a few buildings at most) be mutually exclusive with a vertical farm?

On top of that, there seem to be four pairs of mutually exclusive building branches of anywhere from one to four buildings each, one of which has a national wonder for picking to build it everywhere too. It's a lot to keep track of, and it's hard to immediately check what each branch's net result is compared to the other. Furthermore, the branches don't always seem to be balanced very well against each other; for example, the Aquaculture Lab is almost always worse than the Undersea Mining Platform, which is a necessity for keeping coastal/island cities viable production-wise.

It also seems to go against the general design philosophy of Civ V BNW, which doesn't really do mutual exclusives anywhere but ideology. The design usually focuses less on "doing X locks you out of doing Y" and more on the opportunity cost of doing one before the other. Maybe this one's just me, but I found it aggravating not being able to "build everything", as it were, when I had plenty of production to do so. I guess I'm not seeing why you couldn't just allow all of them to be built in the same cities and nerf the individual buildings to keep things balanced.


General issue #3: I don't know if there's an easy fix for this you could do, but I've noticed that upon reaching FW, the first civ to get there tends to snowball through the rest of it way ahead of everyone else. Part of the reason for this is that the huge increase in specialists means a ton of GPP, and especially Great Scientists. Maybe the techs should increase in cost a bit more as you get through the FW tech tree?


General issue #4: Why the heck can I not buy space stations and space station modules?