Wow, haven't heard that song since it came out! With a long this long, it would've almost made sense to edit the song down (somehow). Myself, I try not to be a slave to the music I use.
It was clear there was a fair bit of padding to the animation, but it still held my attention. Playing around with the background colors a bit more, during the middle of the animation, might've helped.
Was kinda hoping for some clue as to what the kid was waiting for. Putting in little hints as to the nature of the relationship, would've filled this out more completely. If you hadn't used a commercial song, this might've been a fine NATA entry (I guess the day the letter came, could be considered a holiday).
You're a very promising animator, and I look forward to more good work like this in the future!