The hand-crafted campaign and scenarios, do not have any way to adjust difficulty. The ease to gather money is absurd. We end up snowballing forward, able to do everything, and therefore the game requires us to build-out most of the map to have any satisfaction that we did a "decent" job of management. Once you build-out the map once or twice, things get repetitive.

Normal gameplay boils down to finding marginal gains with tactics that feel like hacks and exploits, for example: teleport, insta-switching industries, and many forms of full refund exploitation. These appear to be the only way to find some strategic advantage while on a predictable snowball towards build-out.

In my opinion the fundamental issue is that funds come in so fast that spending it becomes a literally chore. In Custom Game mode there are some settings that allow us to moderate this some. However, 90% of the time, at least one task requires massive build-out of the map. Such as achieve $15M a quarter in passenger revenue. The settings might slow our journey, but the destination is the same: map build-out.

The main part of the idea is a "voluntary rule" to set employee costs at the maximum level. 6 hour days, and 200% efficiency across the board for all departments. The result is to put our focus on engine efficiency.

This should be combined with another voluntary rule: once we buy an engine we will keep it running on the map without abusing the refunds to reset it's route to avoid dead-heading. We will want to adjust it's route much more often. Try to do it legitimately. It's a battle against the game's reset mechanics. But after the train does stupid, then it's ok to reset the route for him. (Normal way is take train off the line, then re-add it.)

The next rule: don't use special cars such as Dining Car, or station add-ons that increase revenue.

The final rule is no bonds. This is mainly to avoid strategies that rely too heavily on industrial profits.

Other exploits exist in the game and more will probably be found in the future. Don't use them. The whole idea of this is to have as realistic a railway as practically possible. Everything should be connected together, maintain your locos instead of frequently replacing them, etc..

Employee wages climb about 240% from maximal efficiency to maximum cost. In combination with no bonds, this has a significant impact on expansion speed in the early game when cities are small. Expansion options are one of the best decision points in the game increasing strategic value a lot. Also choosing which towns to grow will be far more important.

In earlier eras the effect will be more pronounced than in later ones, thanks to a plethora of legacy research effects, which increase revenue, decrease employee wages etc..

In custom games, we can select Barti Shiloh for the additional 30% higher track/bridge/tunnel cost. We might start in 1830 and do no research except what is required for engines. With up to 5 day refunds we can also negate any connection bonuses. A fun challenge is to try to build the Transcontinental on hardest settings with these additional restrictions.