Since when does attention from IGN, Gamespot or Gametrailers determine whether a game is mainstream or not? Those are sites that cater mostly to gaming enthusiasts.
It's not about a lack of TV ads (Madworld got plenty), it's about appeal. We know enough about people and their tastes to say that something like Muramasa, and those other games, are not widely appealing. They're niche.
A game I'm developing with some friends:
www.xnagg.com/zombieasteroids/publish.htm
It is largely a technical exercise but feedback is appreciated.