Crisis Core: Final Fantasy VII/Missions

Aside from the main storyline of Crisis Core, there are 300 missions to take part in. The Mission Menu can be accessed from savepoints, and missions are sorted into categories and sub categories. You can also record your Mission Progress with the percentage in the corner of this menu.

When you open a sub category, you get a list of available missions. Each of these has a rating based from your level.
 * Very Easy — Very simple missions that you will have no problem completing.
 * Easy — Also quite simple missions, that can be easily done at that point in the game.
 * Normal — Average missions, that any decent Crisis Core player should be able to complete.
 * Hard — More difficult missions for more advanced players of the game.
 * Very Hard — Rather difficult missions. Some of these, upon unlock, are impossible, as this is the highest difficulty setting, but the majority can be won with technique, and not stat differences.

If you die in any of the missions, it's not a Game Over. Instead, you simply return to the Save Point you accessed the mission from with all your health restored. To end the mission voluntarily, simply enter the Missions section in the Menu, or by trying to cross the red dotted lines scattered about the missions.