Couple of things I noticed, but keep in mind it's merely my humble opinion and can be taken with a grain of salt:
Not sure if you're like me but I am well aware of the extraneous voices a human mouth can make. I would edit out at least the major clicks and I heard a few swallows in there as well.
The recording sounds like it was done in a medium-sized room with bare walls. When I record narration for audiobooks, I try to make it have no space at all - no discernible sense of "oh - this was recorded in a room", because most people will listen to this on headphones.
I'd add a bit more body to the voice - either by adding a touch (not too much) of compression, or weight like 80-100 Hz, though the voice doesn't naturally have this much bass so it might end up making it sound muddy. I would at least take out the 2K zing that hurts when you turn it up loud.
Same point as Justin - the levels could be more smooth. Bring what you want large up behind the narrator for a moment or edit the narrator to come in after the music comes in. Feather in the music if you want it that loud but don't overpower the voice if that's your message.
I'd make the sound effect of the record mono as if it's happening in the space (like foley) and then make the music start out mono and then gradually pan it into the stereo you've got it at. Because it starts out as source music and then switches to score (I think that's what happens in the story, anyway).
What microphone did you use to record? And what recorder? I can hear a bit of the digital I/O harshness.
But anyways, good job! Seems like a fun project.