I just played through the second episode. The puzzles in this one were better than the first. They were all something that I would imagine the doctor actually doing. There was a repeat of a puzzle from the first game, but it was one of the better ones. And it only happened once. There was repetition of the puzzles again though, although they did make it more interesting the second time when they added obstacles to it.
The voice acting still seems quite uninspired though. It's once again decent, and better than a lot of adventure game voice acting, but not that great. There's one line by Matt Smith where he says a word the same way twice when it's supposed to be said with enthusiasm the first time. The way it's said makes it sounds like the voice-track skipped.
But, the story and music are really good, just as they were last time.