I've been mulling around an idea for a Sorcerer game.
Inspiration: certain cartoons with humanoid demons and such in them. David Trampier's "Wormy," anything fantasy by Vaughn Bodé, James West, maybe in a more serious vein, old children's book illustrations (Arthur Rackham, Sidney Sime).
Demons (aka imps) are little projections of id-charged ectoplasm from another universe, who can be brought into ours via various ancient rituals. The rituals, and their names, are all old school and traditional -- magic circles, abracadabra, names from the Goetia, the whole nine yards. But the demons, once they're here, have quite modern tastes and attitudes. They tend to be a bunch of little vulgarians, perhaps with Needs for boozing or getting high, cult movies or gambling, sating themselves at all-night buffets, or what not. But of course they're bursting with arcane power.
I'm thinking of two different kinds of Sorcerers, primarily. The NPCs are going to include a bunch of pretentious sorcerous weenies, people you love to hate. A grim gothy sorcerer lord, an ancient bearded cultic badass, and so on. The PCs are going to be primarily ordinary schmucks who happen, by design or by accident, to have gotten access to the old traditions of sorcery and gotten involved with them. It'll be kind of like "play yourself as a sorcerer," but not literally yourself, just the sort of person you might know and hang out with if they were real.
So besides the contrast between the freaky old rituals and the down-to-earth imps would be accompanied by a contrast between the earthy demons and the annoying NPC sorcerers.
Anyway, I've been thinking about this for a while, and started doing a little demon concept art last night.