Transport Fever is a very satisfying train game. The early game is all about making the business profitable. After that, resources are basically unlimited. The end game plays like a giant tabletop train simulator, with a focus on fitting to terrain while minimizing gradients and tight turns.

Factorio also has a very satisfying train mini-game, with a focus on complex signaling and dynamic pathing. Thankfully, there are dials to tune down combat. I like to use the "rail world" preset, which disables enemy expansion.