Second season is totally different from the first one. First season focused on surviving in a closed space while fighting off the monsters. Second one mostly takes place outside, in an open space and the main focus is placed on human s greediness and fighthing among themselves. People that will go into watching this season expecting something similar to season 1 might be dissapointed.

Story
First 3 episodes pretty much felt like a good continuation from where the story was left hanging at the end of season 1. It seemed like you know where the story is headed, but then episode 4 happens and there is a big shift in how the story unfolds from this moment. First we have a time skip, which is one of the main points I disliked - we do not even know how much time has passed, main character dissapeared for almost half of the series (and then he comes back again in this horrendous wig ... . Additionally the whole story SLOWS DOWN. Too much time wasted on dialogues between side characters that you could not care less as a viewer. Season 2 generally feels like a setting for Season 3, but it could be done better.

Characters
I dislike what was done with the survivors from Green House. Most of them was killed just to make some screen time for other (mostly bland and uninteresting) new characters. This season introduced WAY TOO MANY side characters and gave too much screen time to them. I could not care less about them. Most supporting characters that we cared for from season 1 are dead. Park Chan Young is the only good character introduced in this season.

Acting
Acting was great but I still find season 1 superior even in this aspect. Not much more to say.

Would I watch it again? Probably not, mostly because of pacing. I still enjoyed it, it was just not what I was expecting. Hoping Season 3 will be what Season 2 was supposed to be.