Manga ending spoilers: So fuck whoever decided to only adapt this into a 12 episode series. They've done an amazing job adapting it but this ending can't afford to be rushed. I absolutely hate that they basically wrote Airi out of this episode. Changing how he got his memories back into what they did was lazy and just plain bad. It also makes me question the ending since taking away her importance to him as being the trigger to unlock his memories would lessen the impact of her showing back up at the very end. This goes beyond "best girl" waifu talk and all that crap. She was a good character and her appearance was what really set the tone of the ending and made it so good, at least to me. So I'm a bit worried about that, especially after how rushed everything else was. I'm assuming lots of other people felt the same as the score for this show dropped from 9.13 to 9.08 in a single day, with not that many more people actually scoring it.
Anime-only spoilers: The bit before the OP was actually done well and I wondered how they were going to fit that in. The modified OP was perfection. The scenes following Sachiko and showing how alone she was were just plain heart-breaking. The reunion with Kayo was really good and I was worried they would cut it or phone it in, but it definitely made me feel stuff. Cancer-chan's development wasn't really that great in either the show or the manga; Satoru's interactions with her were nice and added a bit of warmth to a character that seemed a little cold. Wasn't a fan of how he regained his memories, though, and that was my biggest complaint in the entire series thus far.
Only complaints I had were how sudden that "I remember everything" moment was. It just came out of nowhere. That ties in with my other complaint, which is manga-related; there was a change that I wasn't really fond of in changing the roles of a few characters. I watched this episode with my friend who hasn't read the manga and he thought it was great except for what I mentioned in the spoiler.
We both flipped the fuck out over the OP changes. 10/10.