If you mean the music especially in the second level, I was playing around with the pitch slider in inspector and apparently forgot to turn it back :D I recommend you try doing it next time (if you're using unity). Results are especially interesting when you pull it to the negative side.
Oh, I love pitch shifting so much that I do it in my every project. Especially if you animate it or bind it to ingame events, like mouse movement. Mmm...
