Games like the Spider-Man ones for the Xbox/PS2 that were "open world" prove that open world games that are just OK are not all that much fun to play once the novelty of whatever new thing the game has (swinging from webs across a city in the case of Spider-Man) wears off. I'd rather have a really great linear story to follow than a open world full of boring quests that are mostly the same thing over and over again. There have been some great open world games, but most aren't much fun after a few hours of play time.