Just putting it out there, if you are expecting a high intensity zombie thriller, you will be disappointed. Should that discourage you from watching? No. It's a weird mix between SoL and zombie survival that doesn't feel too out of place. A decent watch if you enjoy both genres. Personally I liked way more than I should and the finale definitely made it one of my favorite series. However I do have some slight criticisms...

I feel like the biggest offense of this anime was not giving Yuki and Megu-nee more screentime. Episode 1 set so much expectations for Yuki's character, only for her to become important right up until the end. Megu-nee as well. She is repeated so many times yet we never see much of her beside a few flashbacks. Heck we don't even get to see how she died or what exactly happened that "day". Just like the other interesring things about the group, never gets explored. However the biggest upset I can think of was randomly introduced "Emergency Manual". Feel like a huge chunk of the story revolved around that plot point and it just gets scraped for a pool episode.
I sorta wish they did toned some SOL parts but it wasn't annoying like people say.

Despite my rants, I think the ending does manages to fix some issues but you get the feeling that some major potential was lost.

So yeah, decent show, worth the watch but you might lose interest halfway.