I think it's got a good strong core to it, the Snowmen and Ice Governess are quite fun villains; but I question the overall decision to have it be the Great Intelligence AND for the Doctor to have just forgotten all about it. I think that's a lil insulting to the original stories and something that it could've gone without.

Jenna Coleman has a great debut... debut? Yeah, let's call it a debut and she's more than a match against Matt Smith. I would preferred Victorian Clara over regular Clara to be the full time companion, but only for having a non modern day companion for once. Her introduction to the TARDIS is an amazing scene and hard to get enough of.

Unfortunately, the entire episode is quite heavily sexualised for no real reason and I think it weighs the episode down not insignificantly.