Special Stages, also called Special Zones,[Note 1] in Sonic the Hedgehog CD are a series of seven extra levels. In order to access them, the player must jump into the Giant Ring that appears at the end of each Zone while in possession of at least fifty Rings.
The objective in the Special Stages is to chase down and destroy all six UFOs in each of them. The player will then be rewarded with one of the seven Time Stones. Like destroying all robot teleporters in the Zones, getting all Time Stones automatically changes each Round's Bad Future to a Good Future.
The Special Stages are ominous environments with winding roads on top of pools. Each stage features different layout and futuristic visual setting viewed from a parallax background.
When entering the Special Stage, the player stands on a square, pseudo-3D board. The player is then tasked to destroy all six UFOs that hover around the stage within 100 seconds. Since the playable characters are constantly running here, the player can only turn left and right with the and use the Spin Jump to leap or destroy UFOs.
Running on the grassy sections of the boards lowers the player's movement, while touching the water surrounding the boards will decrease the player's time by ten seconds. Destroying different UFOs will also grant different power-ups: regular UFOs give Sneakers or Super Rings while blue UFOs give a 30-second Time Bonus. There are likewise various gimmicks set around the Special Stages that the player can use to navigate the boards and reach UFOs.
If the player fails to destroy all the UFOs in time, they will exit the Special Stage. Destroying all six UFOs rewards the player with a Time Stone that falls into the playable character's possession. As the player exits the Special Stage, their Ring and Time Bonuses (based on the player's performance) are added to their Total Score. Should the player collect all seven Time Stones, the Round's Bad Futures in each Zone automatically change to Good Futures. However, the player cannot enter the Special Stages again in normal gameplay. The game's ending will also change drastically.
Gimmicks and obstacles
|Chopper Blocks||Obstacles placed in rows. Passing through a Chopper Blocks makes the playable character come to a complete stop and lose Rings.|
|Fan Blocks||Moving over Fan Blocks sends the player floating into midair. The player can use them to reach far away UFOs.|
|Spring Blocks||Moving over Spring Blocks bounces the player high into the air.|
|Dash Zones||Regular or Mini Dash Zones give an extra boost of speed, usually in their indicated direction.|
|Bumper boarders||Flashy borders in each Special Stage board that can bounce the player backwards or sideways. Depending how fast the player move, the further way they will bounce.|
Special Stages can be replayed in Time Attack after the player clears Time Attack in less than 30'21"05. Pressing left on on the menu screen will view a list of the game's seven Special Stages. Unlike in regular Zones, Special Stages in Time Attack have the "Next" option removed from the top menu.
In Time Attack, the gameplay of the Special Stages has been changed slightly: the time limit is removed and water will not affect the player's progress. Blue UFOs are also not present here.
- By adjusting the codes FM#07, PCM#07, DA#07 (PCM#07, DA#07 for the 1996 PC release) in the Sound Test and pressing START button, it will activate a secret Special Stage with its own board layout and a gigantic Eggman head looking at the screen from the horizon. Completing this secret Special Stage will unlock additional credits where the development staff behind the game's Special Stages are included.
- The 2011 re-release of Sonic the Hedgehog CD features consistent 60 FPS frame-rate that support the widescreen format during the Special Stages. The re-release also includes the following alterations:
- The UFOs that carry the Sneakers are blue, most likely to better differentiate them from the purple ones, which carry Super Rings. In the original, gold and silver stripes on the UFOs (which could only be seen close up) indicated this difference.
- In the Special Stages, the "warning" sound for when time is running out starts when four seconds are remaining, as opposed to the original's fourteen seconds.
- In order to access the Special Stage's Time Attack, the player has to select the "Next" icon, rather than pressing left on .
- ↑ Although titled as Special Stages in manuals, the results screen and Time Attack menu refers to them as Special Zones.