A number of free tutorial videos showing the locations of crystal skull items hidden in the game's original campaign will also be released on the same day.

Click through for the relevant details.

Mission Mode

What: 25 missions (basically a new campaign mode)
When: Friday, July 25
How Much: 800 MS Points

Introducing Mission Mode, a brand-new gameplay expansion for the acclaimed action game Ninja Gaiden II. In this all new game mode, challenge your skills in self-contained missions featuring trials and tribulations not found in the standard story mode. Karma Attack missions task you with obtaining the highest score, while Survival missions give you a single weapon to fight off as many enemies as possible. Take your high scores online with Xbox LIVE and compete with players around the world on the mission leaderboards!

Skull Videos

What: 30 videos that reveal the locations of hidden in-game skulls. Will split up into 3 packs and each contains 10 videos
When: Friday, July 11
How Much: Free!

Skull Video #1: Having a hard time discovering the crystal skulls located throughout Ninja Gaiden II? Use these videos to help you find the skulls, and earn Achievements in the process! This video shows the location of the first third of the skulls.

Skull Video #2 Having a hard time discovering the crystal skulls located throughout Ninja Gaiden II? Use these videos to help you find the skulls, and earn Achievements in the process! This video shows the location of the middle third of the skulls.

Skull Video #3 Having a hard time discovering the crystal skulls located throughout Ninja Gaiden II? Use these videos to help you find the skulls, and earn Achievements in the process! This video shows the location of the last third of the skulls.