Basically an alternate version of "The Last Station". The stations are very small and repetitive, but "Rail or Die" makes up for it with a lot of action during the rides (whereas in TLS there was basically just a rush to fix the locomotive parts and feed the passengers. Much stress, little fun...)
Shooting poor birds with anti-aircraft guns is, honestly, the cruellest and funniest thing I've ever done. The fun-madness combo is a great mechanic to work on. There are those who complain that three types of enemies are few, but I believe that they are sufficiently varied as basic enemies. Maybe you could add some kind of boss, but other than that I have nothing to add.
Now, the real problems: Once you've built and upgraded everything the game has to offer, you can only continue to accumulate materials. I'm sure you are already working on it, but I would recommend, if allowed, to add some new dynamics that require the use of the other materials. Also, a sore point, the medals are buggy and he only gave me the 10 day one, when I actually got to the 50th day and bought everything. Also the ranking gives me a score of 12...based on what? I arrived at day 50...
Beside those things, the game has the potential to be pure gold! Keep up the good work! ;)