Sonic Chronicles: The Dark Brotherhood
Metropolis Ground Zero is a devastated and crushed version of Dr. Eggman's already dilapidated stronghold Metropolis, due to Angel Island falling down on top of it following the theft of the Master Emerald. The streets are filled with uncontrollable robots that have been released from Eggman's Hazard Vault following Angel Island's impact.
After Pir'Oth and the Nocturnus Clan stole the Master Emerald from Angel Island, Sonic and his team ended up in Metropolis Ground Zero. There, they formulate the plan of going after Ix into the Twilight Cage and take back both the Master Emerald and the Chaos Emeralds. Shade, who up to this point had been fighting for Ix against Sonic and his team, switches to their side, as she did not want Ix's plans for world domination to be fulfilled. Sonic and his allies then scrambled through Metropolis Ground Zero to get the resources needed to build the Cyclone, before traveling into the Twilight Cage.
Metropolis Ground Zero takes place in a section of the ruins of Metropolis close to the place where Angel Island impacted the ground. Due to the island's impact, the machine city of Metropolis, which is filled with decayed metal buildings, scaffolds, factories, stories-tall complexes, and trash-filled streets, have been broken even more down, with smashed buildings and even more littered streets dominating the environment.
In the northern part of Metropolis Ground Zero, the edge of Angel Island can be found, with large broken-off boulders, echidna relics, and smashed and/or half-crushed buildings lying next to the island's edge. In the rest of Metropolis Ground Zero, the buildings are still partially intact, but have been heavily damaged by falling debris and the tremors from Angel Island's impact, leaving them with further widespread cracks and large rocks embedded into them.
The streets and rooftops of Metropolis Ground Zero are filled mountain rubble and plants from Angel Island that were scattered by the impact. This has left the streets filled with small crack-filled craters from falling rocks and boulders that are with or without plants on them.
After Pir'Oth Ix stole the Master Emerald from its shrine on Angel Island and escaped, despite Sonic and his team's efforts to stop him, Angel Island plummeted from the sky with Sonic and his team on it, right on top of Metropolis. Following Angel Island's crash-landing, the island's impact force-opened Dr. Eggman's Hazard Vault, where he had stored his robots that were too dangerous and unstable. With the Hazard Vault breached, the majority of the robots inside escaped and began rampaging through Metropolis Ground Zero.
When Sonic came to, he found himself surrounded by his team, all them having survived Angel Island's fall. Sonic brought the news that Ix had managed to get away with the Master Emerald, which made Knuckles despair. While Sonic insisted they should not give up, however, Amy and the other saw that Ix had used the Master Emerald to open a wormhole into the Twilight Cage, which Ix and the Nocturnus Clan planned to use to escape from the Twilight Cage and conquer Earth. As Shade sadly pronounced that the world was now doomed, Sonic began questioning Shade, who revealed things such as what she had realized about Ix's plans, the history of the Nocturnus Clan, how the Nocturnus Clan hijacked Angel Island with the Chaos Emeralds, and how she and the Nocturnus Clan could temporarily leave the Twilight Cage with warp belts. As Sonic assured Shade after her explanation that they would stop Ix, Tails and Dr. Eggman got the idea of putting together a spaceship from the starship parts that the doctor had lying around, so that they could travel into the Twilight Cage and get both the Master Emerald and the Chaos Emeralds back.
With Sonic agreeing to the plan, Tails and Eggman planned to construct the rocket. However, because Angel Island's crash-landing had knocked out Metropolis's power grid, Tails and Eggman were unable to put the rocket parts together. Tails and Eggman therefore went to Eggman's lab to gather the parts for the rocket, while Sonic and his team restored the power grid. Shade, seeking redemption for helping Ix with world conquest and to stop Ix from using her people for his own needs, insisted on going with Sonic, which Sonic eventually agreed to.
Traveling through Metropolis Ground Zero, Sonic, Shade and their team managed to find the three generators for Eggman's lab and activate them. After having activated the second generator, Shade expressed her impressiveness to Sonic and his friends, finding their bravery and determination to stand up against Ix despite the odds inspiring. After activating the third generator, Tails contacted Sonic, telling him and his team that they now needed the Dimensional Buffer in Eggman's Hazard Vault in order to withstand rigors of dimensional travel, and Sonic, Shade and their team went there to get it. Inside the Hazard Vault, Sonic and his team were attacked by Egg Bot, but they defeated it and got the Dimensional Buffer.
Returning to Eggman's lab, Sonic and his team were ready to take off into the Twilight Cage, when Eggman opted to stay behind, insisting that they needed his intellect to guide them through the dimensional re-entry on their way back and to prepare for an impending Nocturnus Clan invasion should the team fail. Agreeing to this, Sonic and his team boarded the Cyclone and took off from Metropolis Ground Zero and into the Twilight Cage.
At the end of Sonic Chronicles: The Dark Brotherhood, Sonic and his team returned from the Twilight Cage to find Metropolis Ground Zero entirely rebuilt. Eggman then promptly shot the Cyclone out of the sky.
- The music that plays in Metropolis Ground Zero is a remix of the music heard in Tidal Tempest (Past) from Sonic the Hedgehog CD.
- Part of the music was also used in one of the battle themes.