Cons first, because to me this is a great game:

- There are no goals, no structure, no incentive to do anything outside of accomplishing your personal real-world transit fantasy. Now for some that is not a problem, in fact, that's THE selling point of the game, but for me, to be able to keep playing for a long time—and this game is designed to be played for a long time; it's a spreadsheet game with the map of the whole world—it needs to have some sort of milestones to reach, otherwise laying one track in Bangkok is no different than laying another track in New York, after a couple dozen hours. It doesn't need to even be a storyline or a rigid quest list, it just needs to be a large list of achievements so that players can get a sense of progress instead of feeling it's just a couple of repetitive actions of laying tracks and setting up lines over and over. Achievements like "connected 2 cities with more than 10 million people each", "have active service for 500,000 people a day in one city", "maintain 95% riders' satisfaction while serving 100,000 customers per day", or "connect 2 capital cities with over 1,000 km distance", for example.

- Another con that also causes the feeling of repetitiveness in the game is that the reward of the game is very simple and linear: just more money, fake number go up. And after playing the game for more than 30-40 hours, you would have more money than you know what to do with. In fact, you can reach the point with connected transit systems in 3-4 cities where the speed of you building new track cannot keep up with the money you can generate, turning the game into infinite money mode that makes the reward meaningless. I think there should be a parallel reward path alongside momentary income, like permits to build in each city or even nation for example, that can be obtained by reaching a certain number of ridership, but can also be bought with money. Think of it as the cities' governments rewarding you with a new contract, or you buying a land permit from them, depends if you build your system as a public service or a private, for-profit company. The income limit also has to be tuned down while the maximum allowed loan should go up, to prevent the infinite money problem but also maintain a good pace of expansion through debt. Because once you build a profitable line, that line will become a passive income source for you forever, and if that income is too high, like right now, you will get to the point of meaningless money faster. Maybe there should even be a progressive tax system to curb the higher end of profit where players start to make too much money for our own good.

- A third con is there is no tutorial, especially for advanced systems like detail scheduling. Not a big gripe considering what type of game this is, most players would just look it up on their own anyway, but a negative point nonetheless.

- The final con is that UI and UX are a bit clunky at times, especially around the track-laying menu and the scheduling menu. Again, not a big negative, but still a negative.

Now to the pros:

- Everything else in the game. The fantasy the game allows, the simplistic but charming and functional visuals, the track system that has just enough detail to be interesting but is not bogged down by complicated details, the freedom to build anywhere in the whole world and build anything from street-to-street trams to continental-length rail lines, the optimized passenger demand map and simulation,... It's an almost perfect, massive, top-down, train tycoon game that serves the unique fantasy of certain players, like those who want to replicate the great rail systems of their nations/regions, or those who wish their country actually had a good rail system but instead have to use this as wish fulfillment (hello there Americans :D).

Oddly addictive :)