Pretty fun.
I had a bit of trouble understanding that opening the fire box door meant fueling it, but the help option confirmed it.
With some more things to balance I think this can become an excellent game.
Perhaps a map where you have a set path (or just the next turn) and you need to choose the right rail in a split?
I know that in the past the driver needed to grab a "Key" while moving for the rail network to know which rails are occupied at any time, or something like that.
Maybe the player needs to lean in the correct direction (Maybe with a QTE) to choose the correct track, otherwise it's up to chance.
Or some mechanic to encourage the player to drive as fast as possible to meet a deadline?
Just throwing a few ideas.