I really like the feeling of mixed instruments with the music box + synth beginning, only stretching further as the track progresses.
The end at 1:44 feels a little like a fake-out - you are leading into more, basically promising the main attraction to start and then it's just another round of the music box and we're done.
Despite the obvious time constraints (that you also mentioned), the listener gets a pretty good idea how this piece would develop if it were to be developed further. Very nice.