This might be considered grimdark fantasy, for all the author seems to think that it is actually a "one-note joke". Hell, I have to disagree. I had as much fun reading this as I'd have when watching any of the old war movies with a small cadre of broken warriors gathering around for one last violent blow out, with all the natural elements of a heist novel, the underdogs (or rats) of a long and vast conflict. 
 It was pulled-off perfectly. 
 So what's the joke? 
 You know all those old YA novels that featured cute and furry mice going along on grand adventures in the wide world we know and love but unknowing to us? Yeah. That's this in a nutshell, only it's DARK and VIOLENT and would make a freaking fantastic and pretty darn EVIL trick to play on all those kids that would be screaming to watch this cute 3D film with cute kitties and owls and mice in a garden. 
 The story is fantastic and holds its own as easily as if it were in a dark fantasy or a modern and gritty Nazi-Occupied war film. It's only the reflection of exactly WHAT kind of setting it's in that makes this so damn funny. :) 
 Nominated for Hugo Novella '16 and I think I like this the best. :)