Crisis Core has been in development for the PSP since 2004 and details have been few and far between about whats going on. Square Enix have revealed some more details today. As we know its classed as an Action/RPG but the combat system will seemingly be original - DIGITAL Mind Wave its being known as according to Jeux France. The memories of Zack will effect how the player combats so depending on the characters present in his spirit, various techniques will become available. Make of that what you will! Images will appear, probably in the upper left corner of the screen during battles to this effect allowing him to perform actions that people such as Cloud and members of Shinra can do.
For the many fangirls out there, its been stated that Reno (and Rude) will appear during the adventure amongst others. Click on the link to see four images! Enjoy!
Source:
Jeux France