metro Metro Interior

This is just a really simple composition I made, intended for a subway interior. I really want to know what better sounds could be made to feel more like you're in a moving subway, so I want help from everyone.

By the way, I know this doesn't use dynamics that much, so I'm probably going to expect that kind of feedback to happen.

I don't think the dynamic range was really a problem. I could definitely hear this in a metropolitan Pokémon game area or something, haha. It's fun to listen to.
The first resolution to a major second in the beginning parts of the melody really caught me off guard.
The timbres of the melody in the two different main sections was nicely done, but could be a little less harsh... at least in how I heard it. Also on those, holding a note there at that velocity for a long time with these sounds a little lonely and awkward. You could do the Billie Holiday method of held notes and taper each note with some vibrato or melisma. 
Also, just from the drums in the beginning, I was kind of not expected D major. Interesting how that came about.
I really like it. Good job!

Thank you for the feedback. Where in the "two different main sections" are you talking about? And, I really don't know what's the best way in your opinion to feel like you're really inside a subway.

@Monarcheon Also, the timbre is harsh? If so, how can I make it less harsh? :)

I know this is super old, but here's a revision just in case...