Daniel Kraus said this quote

Darkness is a defining characteristic of Rotters. But it’s worthy to remember that darkness is just that—it’s dark—and what is being concealed in the dark is not just the horrible and fearsome, it’s also the inspirational and moving. Horror means nothing without happiness; dark means nothing without light. Rotters may make you feel scared, but hopefully it will also make you simply feel. It’s that kind of book, or at least I hope it is.