mm..eh.. i honestly don't think you can improve it it sounds fluent and has a occuring pattern/repeating pattern, and if it's just the song overall all you have to improve is refine the instruments, i once tried no i attempted to make a original song it was so good but my computer died and my progress was lost and i can't recover it so i just gave up , but for a short song it is Good, it just depends if that is the sound your going for and the focus of mood and tone or the message, the theme, if it is intended to sound Anguish or down depressing than i would say you got that down, but for a short song it sounds mild enough, and not too much or over excessive having too much amount of things going on for a short song time frame. i mean if i'm being honest listening to it i got a minor headache maybe frequency waves?, probably just the sake of day and the piercing sunlight shining through my window.