Nice idea, ready for development
I can see a lot of room for expansion here. You have a basic theme, now develop it by adding different instruments. I hear this thing going in all sorts of directions. At :40 I hear a whole bunch of other instruments coming in, and maybe changing the theme from sad to happy, signifying a change in the mood. :) Have it end with a really uplifting sound.
That's just what I hear, I know you were going for a certain "sad" theme, however, the way it starts with that pulsing beat sets it up for something more. You have a great musical idea here. Now you just have to develop and expand it to make it a fully completed musical thought.
Good Luck, and if you want, please check out my works.