It's worth watching because of the cast. They do such a great job! I already like Nam Joo Hyuk's acting but, OMG, Jung Yoo Mi was shining!
Otherwise, the storyline was quite weird and hard to get into. I didn't get bored while watching any of the episodes but didn't enjoy much either.
The cinematography was 7/10 for me. The jelly creatures should've been more realistic. I felt weird whenever I see them. If they've put much more effort into the visual effects, it could've got at least 8.5/10 from me. They wasted the cast and the story with the weak visuals.