Embedded at the end of an interview with Game Informer, Castlevania producer Koji Igarashi hints at just why Microsoft's 360 can't grab that Japanese market they so desperately sought. Apparently, Japanese gamers only like three games, because as Igarashi says, "... if Japanese developers would say they're working on Final Fantasy or Dragon Quest or Metal Gear maybe, then I guess Japanese consumers would take it [Xbox 360] seriously and consider purchasing it."
I never understood the fascination by Microsoft to try and conquer Japan. I always believed that they should have just gone by the Field of Dreams mantra: If you build it, they will come.
Back to the real point of the interview, Igarashi said that a co-op Castlevania: Portrait of Ruin for DS Wi-Fi is not out of the realm of possibility. He says, "It's not confirmed yet because I haven't started work on it. That's why I can't confirm. But actually I'm thinking about preparing a special unlockable stage where you can do co-op over Wi-Fi. Technically speaking, I think we are able to do something like co-op, yes."