I can't say I cared very much for this one. It's a solid episode for all intents an purposes, but it felt sort of...empty to me. Not much happened and it felt too short and yet had too much fluff. The anti-war anti-AI message was great, if a little heavy-handed.

Splice is a fantastic name but not a particularly interesting character. She didn't seem to grieve at all for her dad, and while I like the "dead but not gone" message it was still a little fast. The poor child acting didn't help. Her dad doing all that to save her was nice, but it's an overdone trope that I don't care for at best. It didn't grate on me too much here, at least.

The romantic subplot between the side characters was cute at first, but by the end was starting to feel a little grating and unnecessary.

The Doctor singing to calm himself down was a nice touch. I also liked his speech about blowing the battlefield to dust; I feel like we don't get reminded that he's an alien often enough. Two hearts doesn't feel that unusual anymore, so reminding us that he's a multidimensional being was great.

Ruby's need to know her next of kin was incredibly annoying on a first viewing, and outright infuriating upon rewatch. Even without knowing her biological mother is an ordinary human woman, her next of kin doesn't have to be biological. However far in the future she must have descendents or descendents of friends or family who, over the generations, would have eventually inherited that status. I could see it being a glitch with the ambulance being unable to find her immediate next of kin, or something that would eventually be revealed to be caused by her dying young due to the Doctor (as so many moder companions do), but that's obviously not the way it was written.

A little bit of pedantry: last episode Ruby has supposedly been travelling with the Doctor for six months, but this was her first alien planet. I also don't love that the Doctor is changing his outfit every episode. For historicals it might make some sense, but I wish he had a more cohesive style like older incarnation.

All in all, a perfectly mediocre episode. I don't have much to complain about, but I also don't have any particularly high praise - other than the phenomenal acting from our two mains, as usual - which I suppose isn't a bad thing.