Ratchet: Deadlocked (2005, PS2) - A darker, far more combat-oriented follow-up to the original trilogy.

Nefarious is planning to exterminate all organic life in the galaxy, so they join forces with a few other heroes (or close enough) to stop him. Ratchet and Clank return to Solana to learn that a mad supervillain named Dr. Ratchet & Clank: Up Your Arsenal (2004, PS2) - Continues developing the gameplay formula established in Going Commando further and included an online multiplayer mode.

Ratchet and Clank are hired by the Bogon Galaxy's Megacorp to rescue the experimental Protopet from a mysterious thief, only for the duo to change course once they learn how much danger it truly poses.

Ratchet & Clank: Going Commando (2003, PS2) - Takes place in a new galaxy and introduces RPG-like progression elements to the established gameplay formula, along with collection quests and arena battles.

Ratchet & Clank (2002, PS2) - The original game, where a fuzzy mechanic named Ratchet and a diminutive robot named Clank must team up to stop the Blarg from destroying planets across the Solana Galaxy.

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