Many of the discussions in this forum's non-stickied threads seem to be pointing out the excessive ease of gold, research, hammer, and even culture accumulation. Particularly with the addition of Opportunities (and potentially even with disasters
).
Instead of trying to adjust each of these for balance, I submit that a more elegant solution would be to just increase the costs of mid/late game techs & units/buildings/wonders. In addition, the yields of those buildings might be reduced (e.g., +50% science/culture reduced to 33 or 25%, or per-population yields from 0.5 to 0.33 or 0.25).
This would serve to extend the game more towards the turn limit, at least for those who aren't conquering everybody.

Instead of trying to adjust each of these for balance, I submit that a more elegant solution would be to just increase the costs of mid/late game techs & units/buildings/wonders. In addition, the yields of those buildings might be reduced (e.g., +50% science/culture reduced to 33 or 25%, or per-population yields from 0.5 to 0.33 or 0.25).
This would serve to extend the game more towards the turn limit, at least for those who aren't conquering everybody.