It was definitely fun, and the lost souls were super creepy.

The episode could have dealt a bit more with all those souls suddenly gone without bodies to return to - it seemed odd to me that the tone was so triumphant when hundreds? thousands? of people had just been snuffed.

Almost all of Eleven's adventures leave me confused though - just like this episode, which I enjoyed while it was happening, but afterwards wasn't too sure what had happened. I miss tonnes of apparent clues and references (like to the shop girl). But then the resolutions of those clues haven't been as satisfying as, say, the Bad Wolf season. Maybe I'm just too dim-witted for Moffat's Who!

Fun though. And I like Clara better than Amy without any real justification for it.