The City is a decently-sized quaint town that resembles real-life cities of San Francisco. built on a blocky hill landscape with layered soil, colored in different shades of brown and green grass on top of the hills similar to Green Hill Zone. The City is placed alongside a lake or river, with multiple islands housing several buildings near the main city area. There is also a long, narrow bridge colored red (which resembles the Golden Gate Bridge) that goes all across the city, helping pave roads to get to other islands inaccessible by walking on land.
With Eggman's devastation on the City, the location has turned into an all-out warzone, with various Death Egg Robot sentinels and Badniks scattered throughout, running amok. Property damage is seen no matter what section of the City is shown, with patches of fire randomly spread in the City and brimstone crashing down.
After receiving word from Rouge that a non-strategic assault involving Eggman's forces was happening in the City, Shadow traveled to the town to stop the assault. As Shadow was progressing through, he heard via intercom E-123 Omega being attacked by an elusive enemy, Infinite, somewhere near the location.
When Eggman finally began his plan to take over the world with the help of Infinite and the Phantom Ruby, he began his conquest by attacking the City. Tails along with several civilians were among those who were cornered by Eggman and several Egg Pawns before Sonic arrived to fight back against Eggman. However, Infinite, alongside replicas of friends and foes of Sonic's managed to subdue Sonic, leaving a void in the world that allowed Eggman to conquer the planet.
Five months of warfare in the City would pass before the Avatar, in an attempt to fight back against a powerful-Infinite, would flee from the City, joining the Resistance a month after that battle. About six months after Sonic's defeat, Tails was repairing a broken down-Omega among the ruins of the City when he was ambushed by a Chaos-replica. Classic Sonic arrived through a portal from another dimension to save Tails, who was relieved that another Sonic was present to help fight against Eggman.
Eventually, the Resistance needed someone to go inside the City to rescue civilians when the Eggman Empire broke into Park Avenue, but with the majority of the Resistance's fighters preoccupied with other fights across the globe, Knuckles was forced to send in Avatar to help turn the tide and save the civilians, to which the Avatar was successful at doing so. Later, Sonic would return to this location after hearing word that Shadow was leading Eggman's army against the Resistance in the City. Wanting to get to the bottom of why Shadow aligned himself with Eggman, he encountered Shadow while the Eggman Army continued its attack on the City, only for it to be revealed as a replica created by Infinite after the real Shadow arrived to defeat the imposter. Amy Rose would later report on that Metal Sonic was spotted nearby in the City, to which Sonic and Avatar joined forces to travel to the location and fight the metallic menace, who was also revealed to be a replica.
After the Phantom Ruby was destroyed and Eggman defeated, Sonic and Avatar returned to the City, admiring the view and contemplating on what they were going to do now. Sonic, like always, decided to go on his own way, giving one last fist bump to his buddy before departing.
Other game appearances
Sonic Forces: Speed Battle
In Sonic Forces: Speed Battle, the City appears as one of the three main areas in the game, being referred to as Ruined City, along with Green Hill and Sky Sanctuary,. The tracks that take place in the City are Sunset Bridge, Splash Highway, Red Gate Bay and Red Gate Ruins.
Points of interest
Park AvenueGo to http://sonic.wikia.com/wiki/Park_Avenue
Sunset HeightsGo to http://sonic.wikia.com/wiki/Sunset_Heights