Railroad Corporation

This game lacks many of the things that Syd Meirs' Railroad Tycoon considered and got right over a decade ago. The maps are not dynamic, which really sucks because it's always the same cities with the same commodities, and the same terrain. Replay for the most part is uninviting. The bidding for land and buildings in entirely predictable. Hit the higher bid button three times and you'll win the bid.
The graphics are great although I experienced significant lag when I increased the detail levels of water and trees. My graphics card has handled far more complex rendering so I'm certain this is a poor memory management issue with the developers. The tutorials are relatively useless.. Fortunately, there are enough players who answered most of the questions I had.
Still, with those limitations I still found it chellenging and enjoyable to play. I didn't play with the time limit options. I found some of the time frames to be absurdly short or the game balancers thought that players should know the quest solutions. That took away a lot of the fun for me but without the time limits I was free to build my empire and then meet the challenges with less risk of having the game terminate because I was overdrawn at the bank.
The game's not worth full price but $15 to $20 would buy you a lot of fun.

This is currently the only game in this genre which supports multiplayer. If you want to play with friend then buy it. It may not be perfect but it is good enough to enjoy.
There is something unique with this game, which is the city growth mechanism. Basically, as city grows, the volume of cargo demanded increases, the type of cargo demanded changes, and the changes are too significant for you to ignore.
I will compare it with several games here.
In RT3, the city growth is typically represented by size as well as the industry you build, or automatically spawned, Industries basically determine the growth. Size growth only matters for passenger and mail. In RT3 you play not only the transporter but also the industrial tycoon, which basically determines the supply and demand of the cities, and the industrial goods represent majority of total demands in the city. When there is corresponding industries, you get dozens of carts of loads per year. Without industries, households consume at most 1 to 2 carts of loads per year of products. So basically, in RT3 the player has significant control over city demands. In RC, you can still build industries. However, the basic demands are much more significant than the ones you build, in terms of volume. You may build 2 industries per city. Large cities would automatically demand 3 to 5 types of final products. In RC your power as a tycoon is weakened. You are more of a transporter and less of a tycoon. The uncontrollable changes represents stronger macro economic factors imposing on you.
In Railroad Empire, cities require much more types of goods on each level. When city grows, there are more types of goods demanded. However old demands still persist. In RE, The volume of the goods desired do not change very much. the key difference is still that the demands change as city grows. In RE the stable demands ease your needs to go back to make changes to your old routes. More often you are adding new routes to your system. In RC, however you must frequently change your route settings.
In Transport fever, city demands never change. They only increase in volume as the population grows.
In conclusion, the city growth mechanism is a key characteristic of this game. You may find it good or bad, depending on your style.

I'm recommending this game with a big caveat: It's not anywhere nearly as good as Railway Empire.
Worth playing for the sake of variety if you enjoy the genre, but there are some design decisions that are really weird. The lack of control over trains pathing can be really frustrating.
They implemented signals only a few months after the launch, and even then it's a very barebones implementations (only directional signals). There's no way to make a route go through a specific railway, or use a specific station track.
Sometimes a train will change their pathing seeingly at random, and instead of using a direct track that goes from station A to station B, they will decide to follow a track that goes from A to C to B, causing issues for all other trains along the way.

It's a good game at reduced prices, but I would not have recommended it at full price. The maps are somewhat historical in that city locations are geographically correct. But this means no dynamic maps. There is no change of seasons, so the maps are green year round. As cities get larger they get more "sophisticated" and change their demands over time (wood to lumber to furniture, coal to iron to tools) so a train that is profitable delivering one resource will find in the future zero demand for that resource.
Trains stop at every station between two points which is REALLY annoying.
It's an interesting take on the genre, but nothing really groundbreaking (I did not buy any DLC).

Good business sim game, ok-ish railroad game. The developers are still adding new stuff. I had a lot of fun playing it, and some of the missions require some thinking to get passed. There's no formula to winning that can be applied to every situation. One mission hauling people is a money maker then another mission trading on the commododies market can make you a millionaire. I really like that the trains depreciate, there's banking, you can issue bonds, you can lobby local govs. There's a lot of tools in the tool bag. I don't play many train games, but it seems as though people who do and are really into trains are mixed on this game. I can't believe this game is getting so many not recommended reviews. Comming from not playing train games, this game is pretty cool. Maybe it should be marketed as a business sim/strategy game more than a train game, and that would be the crowd that would love this game.

This is not your typical railroad game. You work for a railroad company. You don't own the company, stations, trains, tracks, etc. The company does. Your job is to manage your part and make money for the company. Easier said than done. It's a task-filled puzzle and it's quite fun!

Seriously, this game deserves more attention. The economy system involves interesting game mechanics like city growth, industries, contracts, lobbying, etc.
The singleplayer mode is addictive and the multiplayer mode is quite enjoyable, but needs more work.