Spoilers for first two volumes ahead:
Pretty good. It was very well paced and the beats came in fast and consistent.
I will say that the ending was a little off. It just felt like there were still plot threads to be tied up.
Overall, I was sad when it was over. Characters really did shine in this one. And when I say characters, I mean the only two that actually ever mattered in the series, Yuusuke and Mitsuki. I'm not saying that as some shipping vanilla drone or whatever, I'm saying that because the doctor has so much screentime in the second volume just to do nothing at all in the third. She was worse than useless. I was actually impressed just how useless she was, actually. I thought she'd at least be pushed forward as some sort of plot device. She honestly should've just been killed for shock value.
As for Tokiko, she at least played a role, and it was fairly bittersweet. I have to wonder if there's not more she could've done, though. They kind of built up a whole 'awakening' subplot just to drop it.
I'll also say that the human antagonists that were hinted at in the first volume, and built up in the second, really sucked. I was expecting some sort of philosophy, as would any reader if they heard antagonists drone on about a 'new world' and stuff. They kind of just served as a comparison to how shitty humans can be, and make Yuusuke look a lot more preferable. I feel like Yuusuke as a character would've been much more compelling without such a device used to redeem him.