How to improve
You already have the first thing: You can make good melody lines and you have timing.
Second you can add a beat or a backup instrument like pads, bass and that kind of things. also you can add automation clips and whooshes...
I used automation clips for the sound at the beginning and at 0:48. Cutoff.
I have bass, but I'm really ridiculously bad with drums. What's a whoosh? xD
Thanks for the review! :D