The biggest success and mistake with this story was Clara's backstory. It was wonderfully written and wonderfully thought out. The problem was it took up half the story, if not more, leaving the rest to be rushed.
This is basically Clara's 'End of the World', but with the plot being pushed aside for Clara exposition.
It's wonderfully acted, the music is beautiful, the visuals are fantastic, concepts were good and dialogue both funny and evocative. The dialogue was a triumph in my opinion.
It's just not much actually happened.
Oh and any scene with that scooter was just silly and not in a good way.