My proposal is simple - Spiderim. Replace every creature and NPC with a spider or spider-based one. The different pc races could be different races of spider, perhaps with Mer being the web-spinning kind and Men being the hunting kind. The various creatures could be all sorts of different spiders with different abilities. And NPC's? I've got 3 words: Giant. Talking. Spiders.
So what does everybody think of this idea? Will the spider-lovers get any luck?