There were a few things in this episode I really liked...
-The Doctor referencing his Granddaughter
-The Doctor's speech to the big bad
-The idea in general of souls being memories and using sentimental objects as currency
-Clara and Emily's interactions
-The Doctor's frantic thinking trying to figure out the mystery behind Clara
-The Doctor's attitude when he's showing Clara her first look at an alien system
However, on the whole, I found the episode pretty lackluster, a lot of it from the production side. The greenscreen effects were laughably noticeable and bad, and the set of the pyramid was confusing (and poor editing during the Doctor's escape from the Vigil didn't help). Really cool-looking monsters like the mummy and the Vigil did fuck all, while the big bad at the end had a silly smiley face. Also, when he imploded, wasn't that also their sun?
Honestly, this was probably the worst "companion's first trip" episode they've done. It felt a bit too safe overall. Great performance by Matt Smith as usual, but his chemistry with Jenna-Louise Coleman in the market scenes seemed a little off somehow, I don't know. Still looking forward to next week's episode as well as Neil Gaiman's! Plus the hopefully end-of-season resolution of who/what Clara is.