TokyoDrift explains that you can actually change the background music for the game. Here are some notes though since there seems to be some bug with it still, as well as some explanation on the highscore server:
And yes, the background-music is crap but you can listen to your own music by putting it to "ms0:/MUSIC/fallballsound.mp3". Some (actually most) mp3s make the Programm to show an error, so load your mp3 to audacity or whatever and re-encode it. Should work then. The game has also the feature of uploading your highscore to the NovaCoding server. In the Package there's a client for looking at these highscores. Since NovaCoding isn't able to buy an own server the free-server sometimes is offline.