Lately there's been a surge of PS4 Game PKG's normally requiring higher Firmware that PlayStation 4 scene developers have been able to 'backport' to work on lower Firmware including Jailbroken PS4 5.05-5.07 Consoles following the PS4 Backporting Instructions to Play 6.72 Games on 5.05 Firmware. 
In recent weeks a PKGTool bug fix was discovered by 3226_2143 and developer m4xton committed a Fix integer overflow in PKGTool parallel extraction (PS4 PKG Tool GUI) on the LibOrbisPkg GIT to extract game files properly.
As a result, announcements were made pushing the PlayStation 4 games official releases back further:
Since then, one of the biggest questions PlayStation 4 sceners have been wondering is: What's involved in the process of backporting PS4 PKG games?
Developer (now Anonymous) notes it doesn't work for retail games (only QA) and responded to this with a basic outline of the PS4 BCP Method steps involved in the trial and error process on Logic-Sunrise.com (now removed), to quote roughly translated: So...
While the decryption passcodes were reportedly included in the leaked server QA PKG's, @MrNiato also suggests trying the Unreal Engine 4 (UE4) default passcode specifically for indie studio titles... although @LightningMods reminds us a decrypted EBOOT and modules are required (which can't be done with a retail decryption key):
That brings us to the last 24 hours or so, where developer @Al Azif confirmed on Twitter that based on a call from StarMelter newer PS4 PKG's with a minimum Firmware of 6.51 are able to be opened up in PKGEditor showing Bloodstained: Ritual of the Night (which ironically is by... 505 Games
) in the screenshot below... here's to hoping a comprehensive guide or video will be made eventually covering the entire PS4 game backporting process for end-users to do on their own. 
Download: Default UDK Passcode
So a few final notes. These PKGs are UE4 PKGs that used the default passcode. The binaries are still encrypted. The chances of actually making them run on your PS4 is low. You can view all of the images/music/etc but have no actual code. This list is where my involvement ends.
They were PKGs made for test/devkits and the binaries were not encrypted.
That's a decent amount of effort to avoid releasing a Future PS4 Jailbreak Exploit, however, it's still possible to Locate a Jailbreakable PS4 5.05-5.07 Console in 2020 so perhaps justified as when one does surface it'll work with the remaining PlayStation 4 games through the console's end of life.
In recent weeks a PKGTool bug fix was discovered by 3226_2143 and developer m4xton committed a Fix integer overflow in PKGTool parallel extraction (PS4 PKG Tool GUI) on the LibOrbisPkg GIT to extract game files properly.
As a result, announcements were made pushing the PlayStation 4 games official releases back further:
Since then, one of the biggest questions PlayStation 4 sceners have been wondering is: What's involved in the process of backporting PS4 PKG games?
Developer (now Anonymous) notes it doesn't work for retail games (only QA) and responded to this with a basic outline of the PS4 BCP Method steps involved in the trial and error process on Logic-Sunrise.com (now removed), to quote roughly translated: So...- Find an official PKG
- Find your PKG's tweakkey and datakey
- Patch the decompilation software .dll with these 2 keys in order to find the passcode
- Recompile the decompression software with your patched .dll
- Decrypt your PKG with its passcode and your patched software
- Extract data from PKG
- "Backport" .prx and .bin files
- Find the missing files (because sometimes the backportage is not complete)
- Rebuild your PKG with the new files
- Create your FPKG
- Pray that it works...
While the decryption passcodes were reportedly included in the leaked server QA PKG's, @MrNiato also suggests trying the Unreal Engine 4 (UE4) default passcode specifically for indie studio titles... although @LightningMods reminds us a decrypted EBOOT and modules are required (which can't be done with a retail decryption key):
That brings us to the last 24 hours or so, where developer @Al Azif confirmed on Twitter that based on a call from StarMelter newer PS4 PKG's with a minimum Firmware of 6.51 are able to be opened up in PKGEditor showing Bloodstained: Ritual of the Night (which ironically is by... 505 Games
) in the screenshot below... here's to hoping a comprehensive guide or video will be made eventually covering the entire PS4 game backporting process for end-users to do on their own. Download: Default UDK Passcode
Code:
Absolver Yes
Ancestors Legacy Yes
Bloodstained: Ritual of the Night Yes
Concrete Genie Yes
Darksiders III Yes
Darwin Project Yes
Days Gone Yes
Ether One Redux Yes
Grip Yes
Hakoniwa Company Works Yes
Journey to the Savage Planet Yes
Jumanji: The Video Game Yes
Laser League Yes
Moss Yes
Moto Racer 4 Yes
Obduction Yes
Paragon Yes
Psychonauts in the Rhombus of Ruin Yes
Raw Data Yes
ReadySet Heroes Yes
Red Goddess Yes
Rime Yes
School Girl/Zombie Hunter Yes
Shadow of the Beast Yes
Shenmue III Yes
Skylar & Plux: Adventure on Clover Island Yes
Snake Pass Yes
Spyro Reignited Trilogy Yes
Star Wars Jedi: Fallen Order Yes
Sword Art Online: Fatal Bullet Yes
Terminator: Resistance Yes
Tetris Effect Yes
The Culling 2 Yes
The Flame in the Flood Yes
Voyage of the Dead Yes
-----------------------------------------------------------------
A Way Out No
AIPD No
Abzû No
Ace Combat 7: Skies Unknown No
Adrift No
Ark: Survival Evolved No
Aven Colony No
Batman: Arkham Asylum (Return to Arkham) No
Batman: Arkham City (Return to Arkham) No
Batman: Arkham VR No
Borderlands 3 No
Caligula: Overdose No
Call of Cthulhu No
Code Vein No
Conan Exiles No
Cyberdimension Neptunia: 4 Goddesses Online No
Darksiders Genesis No
Daylight No
Disaster Report 4 Plus: Summer Memories No
Dragon Ball FighterZ No
Dragon Ball Z: Kakarot No
Dragon Quest XI No
Déraciné No
Earth Defense Force: Iron Rain No
Eve: Valkyrie No
Fighting EX Layer No
Fortnite Battle Royale No
Fortnite: Save the World No
Friday the 13th: The Game No
Ghostbusters No
Gravel No
Hardware: Rivals No
Hellblade: Senua's Sacrifice No
Hello Neighbor No
Hidden Agenda No
Jump Force No
Kingdom Hearts III No
LawBreakers No
Life Is Strange 2 No
Life is Strange No
Little Nightmares No
Marvel vs. Capcom: Infinite No
MotoGP 18 No
Mutant Year Zero: Road to Eden No
My Hero: One's Justice No
NBA 2K Playgrounds 2 No
NBA 2KVR Experience No
NBA Playgrounds No
Naruto to Boruto: Shinobi Striker No
New Gundam Breaker No
Observer No
Planet Alpha No
Pool Nation FX No
Realm Royale No
Rez Infinite (Area X) No
Ride 3 No
Rock of Ages II: Bigger & Boulder No
Rocket League No
Ruiner No
Samurai Shodown No
Soulcalibur VI No
Space Dust Racers No
Statik No
Street Fighter V No
Strike Vector EX No
Styx: Shards of Darkness No
Submerged No
Summer Lesson 2 No
Summer Lesson 3 No
Tekken 7 No
The Awesome Adventures of Captain Spirit No
The Bard's Tale IV No
The Last Remnant (Remaster Version) No
The Outer Worlds No
The Sinking City No
The Turing Test No
The Vanishing of Ethan Carter Redux No
Train Sim World No
Travis Strikes Again: No More Heroes No
Tropico 6 No
Vampyr No
We Happy Few No
We Sing No
We Sing Pop No
What Remains of Edith Finch NoThey were PKGs made for test/devkits and the binaries were not encrypted.
That's a decent amount of effort to avoid releasing a Future PS4 Jailbreak Exploit, however, it's still possible to Locate a Jailbreakable PS4 5.05-5.07 Console in 2020 so perhaps justified as when one does surface it'll work with the remaining PlayStation 4 games through the console's end of life.
