Aw, hurray! That is so cool! After having played your game, I can definitely reaffirm the compliment! It was a really fun game, easy to play, and took me through some really interesting emotions about my beloved passengers.
I think it would be a nice way to develop NPCs for other games as well, although I haven't done that yet.
And yes, totally agree about Terry Pratchett's ability to really make you feel the compelling nature of trains. Even though it was one of his later works where you could see the Embuggerance coming to the fore, it is still a fantastic book and the main reason I liked it was the train slowly coming to life.