Red Gate Bridge mainly takes place on the signature bridge that cuts through the City and the surrounding coastal region. During the events of the game, Sonic the Hedgehog and the Avatar came here to defeat a Metal Sonic replica.
Red Gate Bridge starts out on a red stone bridge on the mainland, just outside the city limits of the City. This red bridge leads through a blocky hill landscape at the coast that has layered soil in different shades of brown and green grass on top of the hills that favors Green Hill. After this area, the player enters a illuminated gray sewer tunnel with numerous rusty and leaky water pipes. This tunnel lead to the Red Gate Bridge itself, which, as its name implies, is a multi-sectioned through arch bridge. This bridge has suffered heavy damage: the concrete roads have been torn up, pieces of the bridge are missing, and much of its framework is bend out of shape. The bridge itself leads across a wide water belt to other coasts similar to those on the mainland.
While the Resistance awaits Tails and Classic Sonic's return from Chemical Plant, Amy reports that Metal Sonic has been spotted in the City. Stepping up to stop Metal Sonic's rampage, Sonic heads to the City, taking the Avatar with him.
Upon arriving in the City, Sonic cannot see Metal Sonic anywhere, despite Amy having confirmed the sightings of him. In that very moment however, a Death Egg Robot sentinel ambushes Sonic and the Avatar. Thanks to the Avatar though, the heroic partners are able to avoid the massive robot's attacks and strike back, destroying it. Sonic and the Avatar subsequently resume their hunt for Metal Sonic. Upon finding him however, they discover it is another replica, and a strong one at that too. Despite this, the two heroes are able to destroy it. In the aftermath, Sonic celebrates their victory by offering the Avatar a fist bump, something which the Avatar happily accepts. With the elimination of the Metal Sonic replica and the Death Egg Robot sentinels with it, the City is finally purged of the Eggman Empire's forces and liberated by the Resistance.
Like in other Tag stages, the player controls both Sonic the Hedgehog and the Avatar at the same time here, with the lead character switching to Sonic when Boosting and to the Avatar when using the Wispon. To accommodate the different characters, the stage has mechanics for both of them. For Sonic, the stage has Wisp Capsules with White Wisps along the way so the player can charge their Boost Gauge. For the Avatar, the stage has Wisp Capsules with miscellaneous Wisps for fueling the Avatar's different Wispons. However, any Wisp Capsule containing Wisps that do not match any of the Wispons the player has currently obtained will be rendered intangible and transparent until the player obtains their Wisp's associated Wispon. This means, for example, that if the player does not have an Asteroid Wispon, then the capsules with Indigo Wisps will be unobtainable.
The stage starts out with Sonic and the Avatar running across a bridge. A Death Egg Robot sentinel soon after smashes the bridge beneath their feet. This initiates a Real-Time Interaction cinematic. During it, the player must press // when the green rings that appear overlap; the better the player times the button presses, the greater the point bonus the player will receive.
During the aforementioned cinematic, Sonic and the Avatar will land on a ledge, looking at the robot. By completing the first Real-Time Interaction here, the Avatar will swing Sonic and themselves away from the robot as it punches the ledge. Sonic and Avatar will then swing around the robot while it fires its eye laser. Once the duo is in front of the robot's eye, the player must complete another Real-Time Interaction. Sonic and the Avatar will then charge their respective Spin Attacks and shoot through the robot's head, destroying it. The two will then fall into a pit with a sewer line through the hole that the Death Egg Robot sentinel punched in the wall earlier. Proceed down the pit's sewer to arrive at the bridge and initiate the Metal Sonic boss fight. The stage ends once Metal Sonic is defeated.
The boss encountered on Red Gate Bridge is a super-sized Metal Sonic replica. During the fight, Metal Sonic will try to stay ahead of the characters, who must chase after him, while attacking with energy pillars and the V. Maximum Overdrive Attack. Also, when the player gets close, he surrounds himself in a protective barrier of Moto Bugs. To damage Metal Sonic, the player has to clear out the Moto Bug barrier surrounding him, and then attack him with the Homing Attack, Wire Attack, or the Wispon. Repeat this pattern until he is defeated.
- Red Gate Bridge is the only normal stage in Sonic Forces where a boss fight takes place; all other boss encounters in the game have an entire stage dedicated to their fight.
- The name and location's design would imply that this stage is based off of San Francisco's Golden Gate Bridge. This the second Sonic level to be based off of the bridge.
- If the players dies during the halfway point in Metal Sonic's battle, the Red Gate Bridge theme will play instead of the Metal Sonic boss theme.
|"Red Gate Bridge"||Tomoya Ohtani||2:57|
|"Mark II Locks On"||Kenichi Tokoi||0:31|