I was really disappointed with how this K-drama turned out. Honestly, I only kept watching because of Lee Min Ho, but even he couldn't save the show for me.
The execution of the plot and the twists were just poorly done. I also didn't think the female lead was the right match for Lee Min Ho's character.
But what really bothered me was the cheating plotline - I thought it was completely unethical. And then there was the way they handled the morula storyline, which I found really inhumane. It was heartbreaking to see that tiny life go through so much, only to be discarded in the end.
I was also frustrated with how the show ended. They killed off the female lead, and then just dropped the whole storyline about the baby without resolving anything. I mean, how was the baby supposed to get back to Earth? It felt like the writers just didn't care about tying up loose ends.