Eh, I would have to agree with madmanmad, but I would also offer this tip, imo it went to long and thats where it went down hill. The beginning is smooth and fluent and all around bad ass, but then it gets a little slugish. Either way, I cant do it, you did it, 8/10.
My suggestion, try and keep both heads moving at all times. At many points, one person had both heads, try and keep it so both have only 1, which makes it more difficult but also more appealing.