This series you might say, is underrated. Yes, underrated. Why you ask? It hasn't reached many people yet. Basically when I started reading this the first thing that came to mind was the titanic plus zombies combined. Was fairly decent.
It did not have the best start, but it picked up greatly later.

Plot (7) after reading other zombie mangas, I can say this is possibly better than HSOD, which most people have read. Not to mention the fact that zombies and being trapped in a titanic is simply brilliant because you're always 'cornered' and have to move on. It did have it flaws, and referenced a movie, but hey, it was pretty good.

Art (7) I won't say this art is bad but rather good, but it's different from what I've seen which is good actually for serious and zombie moments, but the zombies don't exactly look like 'zombies' more like berserkers.

Character (7) the character setting was good for this series for everyone, though the heroine let down a bit, but it didn't annoy me so I bet you can deal with it.

Enjoyment (8) it's not everyday you come across a good zombie series considering how many are bullshit and this actually has a ending compared to others.

Overall (7) while I would like to give this a 8, it fits more like 7.2/10 but comparing to others, this is still great.

I highly recommend reading this, but I suggest you wait until the end of September because the last two chapters are not translated yet.