The people saying they'd take the money and run are fools. You will never need that kind of money to live off of and you can give yourself a mighty powerful salary. I doubt anyone expects you to work for free, and with proper investments all a man really needs is $5million to live comfortably the rest of their lives. The least you could do is give it a try, maybe make a long-term business off the returns of the game.
Anyway, I'd make a very detailed god-game. I love me some Civilization, but there are simply times when I find the mechanics too game-like. I shouldn't be able to just tell my people 'okay, now it's time to learn how to make pots.' I mean, they're just going to turn around and ask me what the hell that is. So more of an organic flow... I figure taking $150 I could build pretty much the best game ever in technical aspects and get depth far beyond anything I've ever seen in such a game. Of course, long before the final art assets are produced I'd have the game rigorously tested to ensure the game is balanced enough that it could still be a paragon of the medium a decade later. With the costs of hiring a staff comprised of the best of the best, advertising, etc. I'm sure I'd still have plenty left for a $100+ million salary/completion bonus and we could even get started on the next project.
You do not have the right to never be offended.