Of the options given in the poll, I chose "Tall Empire Bias." I think wide empires are generally speaking more exciting than tall empires. (Well, administering a wide empire can be more tedious, which is one downside.) But generally, when the pressure is on to expand your empire or perish, that feels fun. When I can comfortably build up 1-4 megacities and just coast through the game, it's less fun.
All of these features interconnect to other shortcomings mentioned:
- The main reason tall is so good is that science is so important.
- Science specialists are very strong.
- The science buildings are so critical that it skews the tech tree.
- The tall social policies are stronger, which biases towards tall, and then which biases towards those policies.
- The late game is made less exciting by a bunch of tall peaceful civs.
- The tall bias is amplified by more peaceful AIs and early war being unprofitable for the aggressor.
- And the AI being peaceful and ineffective at war is tied to still-not-good-enough tactical AI.
And that's tied into what I think the single biggest problem as of Civ 5 BNW "fall patch", which was not present in choices of this poll (although some commenters have mentioned it):
combat unit balance.
Composite bowmen, crossbowmen, frigates, and great war bombers are too powerful compared to contemporary units.
The twin problems with Archery units is that:
1. they're very effective (you can kill enemy units from afar without losing units or even having to heal your units)
2. they're good in
every situation (more versatile than melee, mounted, siege, or naval units):
- Enemy land units? Archers are great.
- Enemy naval units? Archers are great.
- Enemy units invading your territory? Archers are great.
- Enemy units defending their territory? Archers are best (you can shoot and kill their units without ending the turn within 2 tiles of their city).
- Taking an enemy city? Archers are great. You just need one or two melee units to actually take the city. Sure, you can build a couple of siege units if you want to speed up the process, but by the time you've broken the back of the defending army with your archers, those same archers can take down the city in no time. Since your archers can move and shoot every turn, they get to double attack and +1 range promotions faster than siege units.
Other notes on unit balance:
Swordsmen and Longswordmen are too weak to justify researching their techs and securing a source of Iron, when Pikemen are a sufficient replacement, falling between Swordsmen and Longswordsmen in strength and cost. (Pikemen could be nerfed -- lower their combat strength and increase their bonus vs. mounted. Another fascinating suggestion elsewhere in the forums was to move Pikemen from the top-middle science-favoring part of the tech tree down to something like Metal Casting. That might be too harsh, and I like the idea of there being SOME units in the top-middle, but it might go a long way to unskewing the tech tree. Beeline for Public Schools and you'll be a sitting duck.)
Frigates: As mentioned elsewhere on this forum, there is no counter to Frigates except more Frigates, which leads to less interesting gameplay. Their +33% land bombardment promotions are excessive. I wonder if we could lower their attack range to 1, which would make it harder to annihilate a coastal city with a carpet of Frigates, and also limit their ability to dominate land combat. That might be too annoying in other cases, though, I'm not sure.
There are some more minor game design/balance issues I'd like to see addressed, after 1. unit balance and 2. tall bias. I'll just give a quick summary below and save the rest for separate posts.
3. city state quests: late-game city state quests aren't interesting enough. "generate the most faith/culture" quests are predetermined in the late game; some quests tied into World Congress or Ideologies would be interesting. Also some city-state quests encouraging aggression might be nice: I'm not even a warmonger, but "most units killed in the next 30 turns" or "most cities captured/razed in the next 30 turns" sounds fun to me!
4. Allow stacking of military and non-military units belonging to friendly civs. It's cheap and nonsensical that one civ's military units can bar another's Worker, Missionary, or Archeologist.
5. Inquisitors are lame. I'll make a separate Ideas/Suggestions post about how Inquisitors could be improved.