The main late game problem with Anno 1800 is that there is too much money and the fun is gone. And It is also not very nice that investors "produce" money.
Accordingly, the idea is as follows, and I think this is not enough in the game:
1. It is necessary to introduce "inflation":
Inflation occurs when there is:
- unoccupied population (there are more residents than businesses),
- or factories are idle (overproduction, the factory is not turned off, but the goods are not produced because the warehouses are full)
2. Inflation does not raise the cost of construction, etc., but increases the cost of all expenses (ships, maintenance of buildings, etc.), it is may be a progression.
3. When investors does appear, they do not produce money, but "bonds":
– bonds reduce inflation, the more bonds the lower the inflation. Perhaps (it is already necessary to calculate the balance), even enter profitability.
4. But bonds have a peculiarity. They are entering the market, placed in a depository. First, the bonds are located, for example, in the "Royal depository".
But opponents can buy them! At the same time, there is an OBLIGATION to sell bonds. If it is in the depository, anyone can buy it. When an opponent buys your bonds, he begins to receive income from your economy. Here, it is need to think, perhaps at the expense of yours economic.
5. Accordingly, the concept of the "bond rate" is also introduced. There is a rate of bonds of all players. The more powerful the economy / influence / army (need to think about it here) – the higher the rate of bonds of a player.
6. All actions can be performed in the "Bank" building. There it is can also enter slots for different bonus items.
7. Islands can only be bought for bonds. You can't do it for money.
In general, these are the ideas.
Of course, it is need to calculate everything so that the game is balanced. But the fight for money in the late game may reach a new level.
This is not a DLC, this is a fundamental update.