My list (even I still enjoy the game):
- Combat problem. For example, too much credits are given to the defenders. Realistically, attackers should also take advantage of the landscape to a certain extent (except attack a fortified city). Horse archers charging from a hill to a group of axemen fortified on a grassland and lose half of the time is ridiculous to me. On the other hand, some defending units should be able to exercise zone of control. I also believe that one should not be able to see everything within your cultural border, unless you have units stationed there, some structures like fortress or guard towers, or proper tech like optics and satellite. Right now sneak attacks are almost impossible. Fix the catapults as well.
- Give me back the colony. No sense you can't use an iron till a zillion turns later because it's just at the corner of your big cross.
- Too much emphasis on forest chop. It turns out whenever I start in a big stretch of forests, I know I'm going to win the game.
- Late game problem. As I once started a thread on this topic, when you're significantly behind in 1600AD, you'll usually lose. The research for late game techs are also not rewarding, hence not exciting. When you get Alphabet early, you'd say "yes!"; when you get recycling, laser, etc, well... just a tech. Late game battles are very tedious. Late game wonders or projects are not significant.
- Poorly made spies.
- Diplomacy.
- Still rarely allow a truly expansive British style empire that is based on colonization. If you want a city on the other end of the continent you either use communism, build a forbidden city or Versailles (the AIs almost always beat you for this one). Very limited options.
- Some lack of details: advisory screens that give little advice; civilpedia that is not knowledgeable; custom games that not very customizable and tend to forget your last setting; barbarian activity option only insane/ a lot/ zero