Love the concept, I was excited to play! The only thing is I can't understand where the second train is supposed to bring its payload... I lose everytime because it won't drop it at the same station as the first train. Did I miss something?
Expanding the map as we go is a great way not to overwhelm the player to much at the beginning but add more and more tension afterwards. I only thing you'd need a way to indicate more clearly the destination of each train.
I see a great potential for a small yet challenging game, well done!
EDIT: I only noticed the tutorial slide on the itch page. I'm gonna give it another go!