Graphics? Gradients are not that creative and look kind of tacky. Maybe try coming up with a graphic theme/setting, and create a background for it as well.
Music? It makes a game feel more professional. Choose something that won't get annoying over time though.
I think this game is neat, it just lacks professionalism. That's what makes or breaks these games that there are eight million of out there. People play the most professional feeling ones.