Also, I don't think the story necessitates a certain art style
I think the story of a game should always call for a certain art style. Though, I gotta admit, it would be fun to see a game like Doom take place in something that looked like Candyland. Shooting unicorns with a BFG that shoots killer gumdrops sounds like a good time to me.
__________________
Talent, vigor, drive...
You'll eat peanut butter the rest of your life.