I love the non-vocal story telling that's never explained to you, like how the big purple slimes surround the warlock, or how the Lich is always in a corner, or how the Rat king has at least four rats around him, or even how the gargoyles come in pairs and even have their models face the other one
Actually, I'm pretty sure the gnome will always run to a random undiscovered tile if there are any left. Sometimes when you reveal an empty tile, you hear a higher pitched noise than usual. I noticed that the noise also always plays if you click a gnome revealed by an orb. I've also noticed that the gnome always seems to be the last empty tile I reveal. I think it's a reward for clearing pretty much the entire board.