Recently the title in question got an official PC-port, as it was originally a PS3 exclusive. The compression is, in theory fairly easy to decipher, as it's just Crilayla, however all the assets in their relevant ".cpk" archives are encrypted, the algorithm seems to be the same from a glance however some archives aren't original, so its not clear if a different or multiple private keys were used/replaced.
Attached is the only semi-working (QuickBMS) script I can find (
source) that can sort of process some data but falls short very quickly. I'm not very adept at QuickBMS scripting but my guess is the encryption key is incorrect.
I have also attached a sample for anyone interested. For those curious current gains are only ~200MB with the encrypted archives.