This chap spent ages translating and recreating the Japanese only mobile game, you will need RPG maker and the files from the above link to play. It's not perfect but it's the best most of us will ever get. Enjoy!
More at: https://www.reddit.com/r/FinalFantasy/comments/cblzgw/psa_you_can_play_the_crisis_core_prequel_in/
Cross Slash if old