I liked the unique approach to graphics. Played a couple of levels and I have to say, that in my opinion the fact that "opposites attract" doesn't add anything to the overall experience. I think that you could've just went with the same color bullet to make a connection with the corresponding ghost and it would work the same (and also without unnecessary confusion).
Also, I really liked the theme. It's nice to see something original in that matter, nice job :)