The paning and volum change effects are really annoying and the song is not really that complex (though that dosen't have to be a bad thing.) I also dislike that it dosen't loop properly. The meaning behind a loop is that i should be able to close my eyes and not notice where the song stops.
That was the bad stuff.
Now to the good stuff :).
Your song is not complex at all. Again this could be both bad and good.
The song tells a story. Even before reading the title I could imagine the picture of a spaceship in my head. The song would be great for a simplistic retro style 2D game :).
So I think the song was okay. Want to give you 3 but I'll have to give you a 2.5 in order for you to further develop your skills :) Believe me. I'm doing you a favor.