You ruined it.
You ruined what is one of the saddest songs ever by giving it a cutesy feelgood style to it. Everyone was smiliing when they should be all frowning. Maybe you were trying to be ironic, like what the Another Day series does with it's sad song/happy animation style, but it didn't work. The song and the animation just clash and don't fit together at all. In short, animation was good, but completely wasted.
Also, she says "don't you fed me LINES about some idealistic future", not "lies".