A long-lost entry in the Final Fantasy 7 franchise has been fully restored and made playable thanks to an extensive community preservation effort. Dirge of Cerberus: Lost Episode -Final Fantasy 7-, a mobile companion game originally released for Japanese feature phones in the mid-2000s, is now playable nearly two decades after its initial launch.

Preserving Keitai-era feature phone games presents major technical challenges due to obsolete hardware, strict security protocols, and reliance on extinct online servers. Although the preservation team acquired an SD card containing a complete copy of Lost Episode in 2024, the game data remained encrypted and unplayable for nearly two years without the required decryption keys.

To crack the encryption, digital preservationist Yuvi built specialized brute-force software and deployed over 90 GPU-equipped servers across more than 125 software instances. Processing nearly 5.5 trillion key attempts per second, the setup decrypted the game files within 72 hours at an estimated operational cost exceeding $900.

Co-developed by Square Enix and Ideaworks3D, Lost Episode follows protagonist Vincent Valentine through side events connected to the PlayStation 2 title Dirge of Cerberus: Final Fantasy 7. While a partial demo version was previously extracted from a mobile handset in 2023, this project marks the first time the full game has been decrypted and preserved for modern audiences.