Before I actually write about how I felt about the episode, I want to say that the BBC America "Watch Party" thing was really dumb. I don't know if they had premiere festivities like that anywhere else, but for some reason, the channel felt that they needed to hype the show with what looked like a night club party. The host was insipid (though, all hosts for things like this are insipid, so I suppose she did a good job) and I'm not sure she really had any idea what DW was. I'm pretty sure that their "party of fans" was just a roomful of paid actors, because all of them were dressed fashionably, there wasn't a single cosplay among them, and each and every one of them had a Thirteen sonic screwdriver to brandish.
But onto the show...
I liked the episode, and I think I will like a lot more on rewatch, though I don't feel it was a particularly good Doctor-introduction episode. My definition of a good Doctor-introduction episode is that through its story, it demonstrates exactly who the Doctor is. "Rose" and "Eleventh Hour" defined Nine's and Eleven's personalities beautifully, while "The Christmas Invasion" delineated Ten's themes so well that it foreshadowed how he was going to fall. After TWWFTE, the only thing I can really say about Thirteen is that she's quirky. She also has a bit more direct compassion and humanity than most of the other Doctors. If Whittaker drew inspiration from any of her predecessors, I think it would have to be Tennant.
The companions haven't been well-drawn yet, but that's to be expected as the episode was really focusing on the Doctor. I like that Ryan has a limitation without being a full-on handicap, giving him something to work around without being an actual hindrance, though I reserve the right to dislike it in the future if it becomes as all-important to the show as Bill's race and orientation were last season. I like the stick-in-the-mud Graham, obviously a man who is amazed to be alive and who really just wants a comfortable, happy life. Sorry, man - that's not in the cards for you. Yaz is the most undefined at this point. She's good at her job and eager to do more, but I didn't get the feeling that she was overly ambitious - just ready for the next challenge after two years of plebe work. One thing that was pleasing was the "get us back home!" vibe from the trailer, calling back a bit to Tegan and Heathrow.
I enjoyed the adventure, and especially liked that a lot of it involved the Doctor looking at what was around her and figuring things out based on evidence that the humans hadn't really noticed or put together. However, I will say that I am not fond of the cinematography. First, it was dark, which was a necessity since the episode was mainly set at night and had it been set during the day, there'd be no way that the train would have been that empty. (I have recent first-hand experience with that! *grin*) But the darkness also made it oppressive and difficult to see, which is not how I like my DW. Second, since about Series 8 or so, they've opted for a more hard-core sci-fi style - more saturated colors and metal and fancy lights and dirt - and I really long for the more down-to-earth style of "Eleventh Hour" or something a bit more surreal like "The Beast Below", "Gridlock", or even "The Fires of Pompeii".
The one thing that made me happy - which I saw during the clip shown on the Graham Norton show earlier this week - was that the Doctor's gender was not a big deal. It was, "Oh, yes, I guess I'm female now," and done. Perfect. Switching genders shouldn't be an issue to a Time Lady, and it wasn't.
My husband's review: "It didn't make me angry." Which is not something he's said often during the last three series. All he wants is for the Doctor to go somewhere, meet aliens, and solve problems without contrived situations to force Doctor/companion altercations and pompous empty speeches. Though there were a couple of things he didn't like in this episode, he's cautiously optimistic.