Dead Line (デッドライン Deddorain?) is the seventh Zone in Sonic Rush. It appears to be a space station built by Dr. Eggman. Like previous stations, such as the Death Egg, Dead Line is built in the shape of Eggman.
This zone has a new gimmick: gravity change. At certain points, the gravity will be reversed and the ceiling will become the floor, similar to the Death Egg from Sonic & Knuckles. This causes Sonic or Blaze to run at the top of either screens. The zone also features gimmicks such as cannons and maneuverable rockets. There are also vacuums that suck up the player's rings if they were to get damaged near them. The purple Chaos Emerald and Sol Emerald are found here. The song for Dead Line is "What U Need."
After the two Acts, the player faces the boss, except this time the boss is neither Eggman nor Eggman Nega. Instead, the boss is Blaze (or Sonic when playing as Blaze) and Eggman or Eggman Nega will watch in the background. Sonic and Blaze, as bosses, will do new moves that aren't available in-game, like Blaze making pillars of fire and Sonic creating wind. Also, instead of the normal boss theme, Metal Scratchin', Vela Nova will be playing in the background.
After 7 hits, Sonic and Blaze will dash at each other, and the player must rapidly press the A and B buttons to win, knocking Blaze (or Sonic) off of the platform.
After finishing this stage as Blaze, she becomes friends with Sonic, but quickly discovers Cream was taken by Eggman during the battle and heads to the Unknown (also known as Point-W) to fight him and save Cream. In Sonic's story, he asks Blaze if she's okay and the two become fast friends after Sonic teaches her to open up and to not be so hard on herself. Sonic then rushes off to the Unknown (also known as F-Zone) in his story to fight Eggman Nega.
To finish the boss fight much more quickly, (since the opponent jumps to counter the player's attack), the player can jump when he gets close, and shortly he will reach the dash section. For this part, it is easier to play this section as Sonic due to his great speed. At the Dash part, it's easy to beat if the player's fingers keep moving left and right alternating fast on the A and B buttons. The camera shifts perspective rather quickly in the player's favor in that way.
- This stage bears a heavy resemblance to Final Rush from Sonic Adventure 2.
- Act 2 has the most rings in a single stage in Sonic Rush as it is possible to get over 700 rings. This is also the only stage in the game in which the player can get 999 rings. (This does not include using Debug Mode in the classic games, or rings from bonus stages or warp rings in Sonic the Hedgehog 3 or Sonic & Knuckles).
- There is a glitch that may appear in the boss of this zone where the opponent does not make a move for a limited time after the start. This results in the player being able to hit the opponent 7 times quickly without being hurt in the process, yielding an easy S Rank.
- Act 1 of Dead Line can be accessed in the the Sonic Rush E3 Demo by swapping the files over. Leaf Storm Act 1 and Water Palace Act 1 also exist. Dead Line, however, was incredibly unfinished, and was impossible to complete. It is unclear why the Demo has this alpha level, as others levels are from Stages 1 (Leaf Storm) and 2 (Water Palace) and everything between them and Dead Line is unavailable.