If i want to compare season and this, i vote season was better. This season more like about Jang Tae Sang and Yoon Chae Ok life and how they survive for 79 years.
Now for the serious part.
Everything was good from acting, OST, production and VFX, but the story it self is ruined all my expectation from season 1 and also some character did not introduced well.
1. Who is Kwon Yong Gil ? He said that he was grandchild of Kwon Jun Taek, but that's it ? No explanation at all.
2. What is Jeonseung Biotech really is?
3. What is Kuroko ? Is that like a man-made soldier that have a Najin inside it or what ???
4. Who is that Captain Kuroko ? How can he get the Najin ?
5. How can Jeonseung Biotechbreed the Najin ?
This is just a glimpse of question in my head for this season, but once again, everything was good but they rush it as 7 episode and left some explanation.
Now i was expecting for season 3 because Najin is in a bottle of water ? and maybe Seung Jo will make an army with that, or just make a riot for society imo.