I'm an American who is watching the show for the first time and first season ever. I'm really enjoying the season as a whole and I love the Doctor's humor and the show's humor in general. The Doctor is a bit manic, but smart and kind and rather loopy as well and I think Jodie is rocking it. That said, I mostly enjoyed the episode. There were some slow spots, but most of it worked for me, especially the characters. I look sideways at plush toy alien threats, but it still worked in general.
I've been trying to read up on the past history of the show so maybe I missed some parts that would explain the following questions:
Why was the Doctor going on and on about the antimatter power device? Some basic techno-babble about the power supply was enough for the plot but then she went on and on about it like it was deadly important to her and she almost seemed rapturous about the whole thing especially with the camera doing a close up on her as she was doing so, but it had nothing to do with the plot. So what was the deal?
I'm probably wrong, but I thought the Doctor didn't believe in messing with time and people's timelines? But there she was in the far future happily telling people they were time travelers and interacting with people who ended up getting killed and possibly because of her decisions (like in the male medic's case)