For a song created hastily, it has some good vibes, I really liked it. As you said, there is some clumsiness, it not fully "polished", but it gives a good sensation and somehow a nice and interesting piece. The firsts 50 seconds are really soft, I like the contrast between the soft and smooth violin and the heavy bells and brass (I think), it's like I'm wandering in a port or in the streets near of the sea at sunset.
The drop at 50 sec is nice and fits a credits song indeed. I find the acceleration at 1:06 sudden, a little disturbing as it feels it comes out of nowhere. The ending is also brutal, I think if you had built it up for a few seconds more with adding more instruments to drag it then to end it on a conclusion, it would have been a great ending.
But this is really a cool idea with good vibes, I hope you'll take time to polish it after the jam, would be too bad to give up a nice music !