http://www.strategyinformer.com/news/1746/microsoft-to-release-25-new-missions-for-ninja-gaiden-ii
Microsoft announced today that it will be releasing 25 new missions for Ninja Gaiden II on Xbox 360, which is said to be the equivalent to a whole new campaign mode.
The Mission Mode pack will be released on July 25th, priced at 800 Microsoft Points.