Kerwan

Kerwan is the planet known for housing the massive city of Metropolis.

Ratchet & Clank
Following the lead they found on Novalis, Ratchet and Clank go to Kerwan in search of Captain Qwark. They arrive on the planet to find Metropolis crawling with Drek's troops. As a first order of business, they decided to visit Al's Roboshack. Once they arrived at the shop Al informs them that he hadn't seen Qwark since filming the commercial two weeks prior. Paying Al a visit doesn't prove to be totally useless, however, as he offers to upgrade Clank with a Heli-Pack for one thousand bolts. Ratchet bought the upgrade, which allowed Ratchet to perform boost jumps and stretch jumps as well as glide.

After leaving Al's Roboshack Ratchet and Clank headed for a nearby train station. At the train station was, naturally, a train. They boarded the train to find that an Infobot was sitting near the cab. Unfortunately, the train was also carrying multiple Blarg Commandoes. They fought their way to the front only to have the Infobot run away. After a short run they found that the Infobot had only gone a short distance. Ratchet and Clank viewed the message on the Infobot and saw Drek communicating with his Lieutenant on Eudora. After a little convincing Clank agreed with Ratchet that heading to Eudora was in their best interest.

Before leaving the planet, Ratchet and Clank decide to look around the city a bit more. The come across Qwark's fitness course, complete with an automated Qwark Robot. Clank humorously mistook the robot as the real Qwark before taking on the course to obtain the prize the Qwark Robot mentioned in his welcome speech. At the end of the course Ratchet and Clank found Qwark's fitness trainer. Indignant about the duo's performance, she forced Ratchet to pay one thousand bolts before giving him the prize; a Swingshot. The Swingshot allowed Ratchet to use Versa-Targets and swing from one place to another, which allowed Ratchet to get out of the final area of the course.

With their business finished on Kerwan, Ratchet and Clank left the planet.

Ratchet: Deadlocked
Sasha Phyronix is the mayor of Metropolis during Ratchet's participation in DreadZone. She sent Ratchet, who she knighted as new captain of the Starship Phoenix when she left, a message asking about the well being of her ship before DreadZone boards the Phoenix and abducts Ratchet, Clank, and Al.

Ratchet & Clank: Full Frontal Assault
Metropolis appears as a multiplayer map for Full Frontal Assault, but is never involved with the game's campaign.

PlayStation All-Stars Battle Royale
Metropolis is also featured as a stage in PSASBR. The stage begins as the Metropolis cityscape and features conveyor belts pushing around various items as well as a grinder pit that occasionally opens up. The stage also features the Qwark statue from ToD in the background with the real Captain Qwark posing next to it. After a certain amount of time, rain will begin to fall and the stage will flood. The Hydra, as featured in God of War, will burst through the glass walkway in the background and its multiple heads will attack players for the remainder of the match. Once the match ends, Qwark will battle the Hydra in the background before dominating the main head and riding into the distance.

Appearance
In the original game Kerwan appeared to be an ecuminopolis, with grays and whites covering the planet's surface. However in UYA the surface of Kerwan seems to be very Earth-like. The image used for Kerwan's orbital appearance in UYA is, in fact, a mirror image of Todano's from GC.

On the surface of Kerwan, the only area ever visited by the player is the city of Metropolis. Metropolis is a very crowded city with skyscrapers as far as the eye can see and never ending sky traffic every. Whether or not Metropolis is the only feature of the planet is unclear due to the inconsistency in orbital appearance.

In the first game, the section of Metropolis visited by Ratchet and Clank features Al's Roboshack, a train station, and Qwark's fitness course. Al's Roboshack is easily identifiable by the large statue of a robot holding a wrench that sits atop the building. The inside of the shop is littered with robot parts and contains a small work desk for Al. Past the Roboshack is lots of luggage, presumably stored there by the nearby train station. The train station itself also features lots of luggage as well as the trains themselves. The trains at the station are red with grayish black highlights and feature exclusively flatbed cars, making them freight trains.

Qwark's fitness course features three floating sky islands. One features a rock pillar with grass or moss growing where it is able. Two features a strange machine pillar with platforms that slide in and out that most be traversed to reach the top. The third island is used for contestants to try out there new Swingshots, as the island only features platforms and Versa-Targets from which to swing from and grapple to.

Trivia

 * Metropolis shares it's name with a realm in Spyro 2: Ripto's Rage!.