Sky Fortress Zone

Sky Fortress Zone is the fourth Zone in Sonic The Hedgehog 4: Episode II, and the ninth Zone in the full game. The level takes place above the clouds as Sonic and Tails persue Eggman on the Tornado before invading his massive airship.

The stage shares the same theme as Sky Chase Zone and Wing Fortress Zone from Sonic the Hedgehog 2.

Title(s)

 * Act 1: The Tornado Takes Off! - Sonic is flown by Tails in the Tornado to pursue the Sky Fortress. In this act, the goal is to knock cannon balls into Metal Sonic's aircraft seen in the background.
 * Act 2: Infiltrating the Sky Fortress - Sonic and Tails enter the fortress, which is similar to Wing Fortress Zone. There are some sections in the stage that evolves running on walls.
 * Act 3: Mile-High Mayhem - It still takes place on the fortress, only it's now in a sunset setting. The ring shooters from Death Egg Zone return here.
 * Boss: Showdown in the Skies - Sonic and Tails board the Tornado again for their second fight with Metal Sonic, who uses his aircraft to attack them.

Badniks

 * Bubbles
 * Balkary
 * Turtloid
 * Clucker
 * Fullboar

Trivia

 * Similar to the levels it borrows its tropes from, Sky Fortress Zone's name references both Sky Chase Zone and Wing Fortress Zone.
 * Like Sonic 2, the zone precedes a final showdown taking place in Eggman's Death Egg, this game being the Death Egg Mk. II.
 * Act 1 of Sky Fortress Zone, along with Act 1 of Death Egg mk.II Zone, are the only two acts where the player cannot enter the Special stage.