Well, someone else has to work on the series. And that someone else is Yosuke Hayashi, the new leader of Tecmo's Team Ninja, and the man responsible for where the series goes from here.
Since I had the chance to speak with Hayashi at E3, I put the question to him: what's next for Ninja Gaiden?
"I think the series has a definite future", he said. "In fact, I already have a concept for the next game in place". As for what that concept is, Hayashi was coy, though he did tease that some aspects of the upcoming Ninja Gaiden 2 Sigma might make their way into a future Ninja Gaiden game.
"The online co-op in Sigma 2 is one step, maybe. It could be a testbed for the future", he hinted. "But regardless of whether that works or not, yes, the foundations for a future game are already there".
So relax! There will be more Ninja Gaiden. In some shape or form. Whether you like it or not.