Train people are dang pleased with this line operations sim because it's not too hardcore, nor too simple

pcgamer.com:

A new train game is picking up steam in the train game community, with Railroader picking up 97% positive reviews on Steam since its December 7 Early Access launch. A sim of both driving the trains as well as routing them, choosing cargo, and picking passengers, Railroader looks to appeal to both the sim crowd and the less-hardcore folks who enjoy games like Euro and American Truck Simulator—even roping in a few strategy and transport sim types who enjoy games like Transport Fever.

Set in the Appalachia region in the era when American railways were switching from Steam power to diesel-electric engines, the «transition era» in railway enthusiast parlance, Railroader is focused on the day-to-day operations of the whole railway rather than just yourself as a single engineer running their train. To that end it includes jobs not just driving, but working the traffic control system as a dispatcher. 

To be clear before I go further, Railroader does include one of the most important things you can do with a steam engine: Pull the lever that makes the whistle go choo-choo.

The most interesting thing going here—besides the choo-choo noise—is that it includes cooperative and solo play, scaling accordingly by also providing AI railway engineers to run trains when you're not present or when you're at the switchboard. That'll let you play by yourself at any level, or run a multiplayer server that your friends (and strangers) can join in.

I'll also say that this one's got a place near to my heart, as the setting is based on the lovely mountains of western North Carolina. With its focus on the broader network of the railroad rather than single trains, this thing's about the place and time, and the business of running it all, rather than