Some Things To Consider

Land Mines - I think there should be a special unit which can lay a certain amount of land mines a day, and they basically can block a road from any nation passing over it. It would hurt you or your allies as well, but you should be able to locate them. Maybe Intelligence Spies can locate them as well when spying.

Trading Researches - One of the trading options should be researches, and allies of your can trade researches to you. Maybe there should be a limit of two or three researches per game though to keep it from getting too out of hand.

Intelligence Spies - I think that Intelligence Spies should be able to discover what your opponents are researching. That would make it that you knew what was going to be coming at you within the next week or so and let you start to prepare.

Military Spies - Military Spies should be able to “confuse” enemy armies and make them march back to their city or even into allied lands. I think it would be really cool if this was implemented, because then you could have them hop on a boat and do nothing in the middle of the ocean until found. Maybe Military Spies should only be able to divert an enemy course when located in the capital.

Levels Should Do More - When you level up in the game, it doesn’t really give you much more than bragging rights. Perhaps it should be updated that for every level you grow in the game, it gives you one extra gold per level at the end of every game. For example:

Player: Level 44

VP Owned: 100

Gold Value per VP: 5

Gold Earned 500+44

General’s Staff - This should be a unit with 0.5 attack and defense in every stat, but who increases the morale of all soldiers he is with quicker than usual. It would make units heal in enemy territory as well, but would be vulnerable if hit by planes. Maybe there should be a limit of 5 General’s Staff or such.

Transport Ships - Do you ever get the feeling that the water is not much more than glorified land? I do. It gets really tiresome when an enemy infantry which was just sitting in Okinawa pops up on my totally undefended coastline unchallenged and proceeds to take half my Continent and bring all his friends along. I think there should be transport ships. 0.5 defense in every stat, but can carry a certain amount of units per level starting at 2 and growing to 8. Maybe Tanks take 2 space. This would make it that we could halt invasions before they even board the boat. It would also give us a chance to see their transports at harbor, and start fortifying the beachhead.

Balloon Troops - Counter Spies should be able to deploy balloons in your city which look like soldiers, and planes flying overhead and spies can be tricked into seeing something which they aren’t.

Alliance Ties Stronger - It should be created that if you and another faction have Map Trade, you have to put your relation back down to Peace for one day before attacking them.