I think you should add more sounds to the background so it doesn't sound hollow...if that makes any sense. A lot of music will have something like a lead synth, with a bass, and some chords playing in the background, all at the same time. although at times you do have multiple instruments playing, they are all playing the same notes so it makes them sound like one BIG instrument combined. I will say though that you are progressing a lot faster than I did