Sonic Rush: Sonic Story Part 13: Dead Line Act 1 & 2
The last regular Zone in the game. Eggman's next space base! Its music is the source of the game's main menu music.
This also means that it has the last and hardest Special Stage for Sonic to complete.
For the actual level itself, being in outer space like the Death Egg & Egg Utopia were. Sometimes you get to run upside-down through the stage thanks to reversed gravity. You may have to hang on to reckless rockets that you will have to steer.
And then there's how different the boss of this Zone is...