It begins with lots of rails and armored trains, and proceeds to a more base-like atmosphere as the level goes on. This level's main gimmick is the giant cannons out of which the team is shot multiple times during the level. There are also giant capsules (used to create Shadow Androids) spread throughout the level, as well as giant trains, which must be boarded and destroyed to proceed. It is revealed in Team Sonic's story that the heroes believe that this is Dr. Eggman's ground base within Rail Canyon.
Team Sonic must destroy Eggman's base at the mountaintop to reach him, Team Dark must infiltrate the base to stop Eggman, Team Rose must find Eggman's base to rescue Chocola and Froggy, and Team Chaotix are instructed to destroy thirty Shadow Android capsules to prevent their transport with the Egg Fleet. Eventually, all of the teams make it to Eggman's HQ. However, Eggman has a more powerful version of his last weapon lying in wait. After the battle, each team discovers that the Eggman they fought was a fake. Unknown to Team Sonic and Team Dark, the fake Eggman turns out to be Neo Metal Sonic, who manages to copy Sonic and Shadow's data.
Team Chaotix mission
For this assignment, the client needs Team Chaotix to destroy thirty Capsules in the stage. The extra mission requires them to destroy all fifty capsules in the stage. The number of Capsules encountered upon reaching each Checkpoint is as following:
Through a glitch, it is possible to grind on the rails in the tunnels.
It is possible to access more of the stage as Team Rose. The player must go to the end of their stage, get on the rail as Cream, and at the rail's high point, jump off and fly towards the triple-rail behind the goal ring. Cream must have advanced to level 3 in order to do this. This allows the player to play through more of the stage then normally possible.
When Team Sonic arrives at the first giant cannon, there is a door that cannot be opened with a switch. To barge through the doors, there is a cannon that aims the door. You must switch to Knuckles and then fire the cannon towards the doors.