Metropolis Ground Zero is the setting for Chapter 6 ("Black Hole Sun") of Sonic Chronicles: The Dark Brotherhood. After Imperator Ix removed the Master Emerald from Angel Island, Knuckles' home does what it always does in these situations: crash. But this time, there's no ocean to cushion the fall; the aerial continent lands right on top of Eggman's Metropolis.
Ground Zero sees the Sonic's team battling through the rubble of what is now a doubly devastated machine city, half-crushed by mountains of debris from Angel Island. Eggman's Hazard Vault has been broken open by the impact, sending crazed, unstable robots rampaging through the streets. Procurator Shade, the game's principal antagonist up to this point, switches sides and joins the party, claiming she wants no part in Ix's cosmic megalomania. After restoring electricity to Eggman's weapons lab and collecting necessary components to build a spacecraft (the Cyclone), Sonic and friends are able to follow the Nocturnus into the Twilight Cage, leaving Eggman behind to "guide [them] through re-entry on the way back" and prepare for an impending Marauder invasion should the team fail.
In the end sequence of The Dark Brotherhood, the team return from the Twilight Cage to find Metropolis entirely rebuilt - and bristling with weaponry. Eggman promptly shoots the Cyclone out of the sky in something of a cliffhanger ending.
The music used in this level is a remix of the music from Tidal Tempest (Past) in Sonic CD.