It's a classic horror survival manga, I wouldn't say its execution is anything new, but the monster designs are very cool, I found myself looking forward to every new monster's appearance and attack specialty. Other than that, the characters were okay, wasn't really feeling anything for any of them, saints or assholes. Main character had the typical "loser backstory but suddenly is the most capable in a disaster", gee whiz man. All in all a good read, don't take the characters too personally or you might get unnecessarily upset. For certain readers: Yes this does have rape, and yes it's as random and shoe-horned and they usuallyare.

Have fun!

Characters: 5/10
Worldbuilding: 8/10 (Monster design is carrying this rating)
Plot: 7/10
Art: 9/10