Ninja Gaiden Sigma 2 may not be coming for a little while longer (it now has an official October 1 release date in Japan), but details on the PlayStation 3 sequel update are beginning to trickle through the Japanese game media. Top among the news this week: the announcement that Sigma 2 will have online co-op, though not as part of the main game story.
According to Famitsu magazine, Sigma 2's "Team Mission" mode will offer a wide selection of one-off missions, which you can choose from freely and decide which characters you want to challenge them with. Having a second player is not a must -- you can play through the missions with a CPU-controlled ally -- but playing online is half of the fun with this sort of thing, right?