I was surprised at how much I actually enjoyed this episode, since the rest of the season has been admittedly a little rough for me.
Peri and the Doctor finally feel like they don't want to jump at each other's throats like every five minutes (both literally and figuratively), which I admittedly really enjoyed. To be fair, I also thought Attack of the Cybermen was fine, but in this episode, I actually also liked the side cast and the world-building a lot, compared to the prior one.
At some points, the pacing felt a little off, but for the most part, I felt like the episode ran along smoothly and fit well together. The Doctor really got some nice Doctor-y moments, and Peri got some time to shine aswell.