Great job!
I forget who said it, but the bits of silence "snapped me back into reality." Were the silent parts intentional? Seeing as how this isn't a "busy" mix, the silence wasn't needed unless you were imagining some kind of scene, but that depends on the mood you were going for.
I do think that instead of abrupt silence, maybe crescendos and decrescendos would work well in those spots (being careful of course) - especially since I heard the piece in movements. It would be beneficial imo to have them connected somehow.
Note, I don't mean every time a movement ends and a new one begins; however, place where it doesn't seem constant (volume); however, you don't want listeners to fall of the face of the earth.
Which brings me to the ending. I would have applied a fade. It's up to you, but here's why I would have done it:
I'll use the analogy of a car. Notice how it skids when you slam on brakes trying to stop? Albeit, as seen on tv and film in dramatic fashion, it's stops just in time. However, I would say, that it is slowing down (much faster because of the pressure applied when slamming the brakes).
The last note (by length and volume) simulated this, but there's the possibility that you slammed into something still. A fade would imply audibly that you slowed down and it's up to the listener to decide if you barreled right into the object, just grazed it or stopped within inches of it.
That's alot to say for one note, I know, but that is what came to mind upon hearing it. I didn't say what you did was not okay as it depends on what you wanted to convey, but I do think it was Beagle when critiquing one of my earlier pieces, said this: "I'm not a fan of abrupt stop and starts!" And truth be told using the car analogy, they aren't either. (Don't drive a manual in the city! haha!)
I apologize for having rambled, but I did enjoy the piece and I do wonder what the inspiration behind it was.