Because of the movie
To start of with some good things, I like the song itself and I think you made good use of the intervals of the music by arranging your change of movement according to it.
But... The whole film seems like it was your first try out sort of... It was all the same. Continuously putting every word in the screen when you spoke it out, the same movements, using 'beginning' tools to make pictures reform itself. It just looked too simple for this song.
Since this submission is more about the film then the music if you ask me, I can't give you a better score. So either keep on practising or try to collaborate for such projects next time would be my advice :-)