Wow. You tried to make rhythmic sounds that evoke the sense of a train, and as far as I'm concerned, your method payed off.
The music has a sense of adventure. In my mind I keep switching from an old-style tunnel with a steam locomotive to riding a modern subway, and back again. Invoking multiple images is difficult but you did it.
The intention is loud and clear. No notes. :)
More info about how I review music here: https://codefreq.newgrounds.com/news/post/1089806