Go to the PS3 settings menu and select "System Update."
Choose "Update via Internet" and follow the on-screen instructions.
Wait for the update to complete and restart your PS3.
Single Player Campaign: Fully playable from the beach to the finale. All QTEs, upgrades, and cutscenes work.
Performance: Framerate is identical to the standard 4.xx release (approx 25-30 FPS on OG PS3, 30-40 FPS on Slim).
Multiplayer:Broken. The multiplayer mode relies on dynamic SPRX injection that conflicts with the 3.55 resign. You will get a DNS error upon searching for a match.
Trophies: All trophies unlock normally if your CFW supports PSN connectivity (though syncing on 3.55 is risky).