A game. I'm looking this and thinking they would say, "Well, for the details regarding the visuals that you are picturing, we would have to start a new engine, aside from that, you are looking at about four hours worth of cutscenes, and a mass amount of gameplay." Even with crunch time, I think the game would take years to finish, and I don't think it would appease to most fans here.
Most fans would think, "Oh, we want to see Kasumi, Ayane, or Ryu as the main protagonists! If they're not, I'm not buying it!" I want the game to have an emotional story, and that the fighters who aren't ninjas get a chance to develop.
That would be cool! And yes, having a game where the non-ninjas would get some development would be great! 5 games in and the focus is still on the ninjas...