Fan raeg and spoilers, ahoy!
Well, let's see. First, Amy and Rory go from Adorable Forever Couple to Raging Hatefest entirely off-screen. This goes on long enough for them to separate, file divorce papers, get them approved pending final signing, and generally build up a lot of rage. All that is established in the first scene with each of them. It's kind of a wrenching change, but that's what we're asked to accept, and given the amount of offscreen time, I can justify it. Doing that offscreen can be really bad storytelling, depending upon what you do with it, but it can also be done perfectly well.
Guess what happens.
Okay, next, all that is betrayed in terms of reactions and interactions within the next three minutes of episode time. That's terrible writing. It's jerking the little puppets around to Make Character Arc Go. This doesn't even have the excuse of months of off-screen time; first you ask us to accept nontrivial amounts of time have gone on (time for the above), then immediately ask us to pretend none of it had any emotional impact.
Characters lying to the viewer is part of storytelling. And that's supposed to be what's happening here, except it's not; it's writers lying to the viewer in the story, which is lazy bullshit.
BUT WAIT! IT GETS WORSE! Well, okay, then other plot happens and a lot of that is pretty cool. But we aren't talking about that part.
Suddenly there's a nasty emotional turn as Rory coughs up in Wristband Sacrifice Mode that He's Always Loved Her More And Everybody Knows It. "I'll save your life, but I want to make sure you know you don't deserve it." That's the only genuine emotional shiv levelled in the entire episode, which makes what happens later even worse. Tho' to be fair, it is the one line in this story that you might expect to see out of an angry divorce couple confrontation, and that's good...
...except that it then the wristband swap offer becomes emotionally motiveless. Had he said, "I've got longer - I'm not affected, we can halt your progression and it won't have enough time to do much work on me," that would've been - as Rory put it - logical about it. But no: he went for the emotional shiv + sacrifice line at the same time. The only time you do that is when, okay, you still have some love, but you have a lot of angry hate built up.
(Of course, all that is cheated by Magic Silver-Age Superman Doctor turns out not to need one somehow, which means the whole thing is meaningless anyway. Of course, he let that go on for a while to "fix their marriage;" that doesn't help this arc.)
BUT WAIT! IT GETS WORSE!
Then! Amy comes out with! I FAKED EVERYTHING BECAUSE I CAN'T HAVE YOUR BABY!
And yet again Steven Moffat defines Amy by her womb. He's got a grating habit of doing this. I've handwaved a lot of it off, but yet again? That's one time too many.
Now, all that said, I'm fine with the whole, "Amy and Rory break up over children." That's reasonable, and sad, and can be done well. It's not a story I particularly enjoy watching, but it makes emotional sense. Except, of course, she's apparently made up this entire other story and set of reasons and is driving him away because that seems... like... a good idea? Really? That's stupid.
Well, humans are stupid, I'd live with it, except...
THEY GET HOME AND EVERYTHING IS SUDDENLY FINE.
Steven Moffat, I dare you to make less sense. Seriously. After all the emotional hell they've put each other through, suddenly, everything is supposed to be just fine? Rory is all pumped?
Either this went on for a while (as required, really, by the opening scene) or it didn't (and the writer lied to us). If it's the latter: BAD PUPPETEER! BAD! If it's the former: that shit has emotional repercussions. I don't care if you had secret other motives; all that anger and hate you generate doesn't vanish.
Unless it's Superfriends-level emotional writing. And even then not without revealing a secret robot double.
Not one scene in that plot - past the setup, anyway - made any sense at all emotionally. The entire arc felt like watching Punch and Judy being yanked back and forth by a children's puppeteer who had slammed back one too many at lunch. It all rang horribly false, and inside, had that stinky bonus nugget of Moffat Thinks Women Are Wombs in the centre.
This episode honestly had me thinking, "Why am I watching this show anymore?" If this is the new normal, I'll be stepping away for a while. I've got plenty of Big Finish audio productions to make me happy.