Haha, just kidding, that'd be impossible but also amazing. And you won't get what I'm talking about if you don't read Homestuck .__.
How about a game focusing on alchemists that are making a resurgence in the modern-day world? Maybe they're kinda like, terrorists... or you /are/ the alchemist! Or you can play as two characters, one against them (like a modern-day scientist) and one with them. Or maybe only one is available by default, you'll have to unlock the other character! If the alchemists win, the world slips back into the medieval times, and all our progress in the past millenium will be lost, but if the scientists win, the last traces of magic in the world will be gone forever :D
hehe, just took the ball with this one and kept rolling with it. Might sound kind of cheesy, but a lot of cheesy games can get a huge fanbase by making a good game with it. I'd so buy this game, if it looked good enough to me.