You go through this stage each time you begin a new game. Use this area to practice your moves and grab all the Rings you can. Stand over holograms to open gates.
— Description, Knuckles' Chaotix manual
Isolated Island, also known as Practice Stage, is the tutorial stage in Knuckles' Chaotix. It is simply a starter area with no Badniks, hazards or bosses, allowing the player to practice the new gameplay feature introduced in the game. In the Scenario Quest, the player goes through the 5-Level Introduction place, whereas the player can enter the 4-Level Training place outside the main game.
When selecting Scenario mode for the first time, the game starts off here as Knuckles, after a few seconds into the stage, the player stumbles across Dr. Robotnik. The Doctor is shocked by the player's entrance and flees using his trusted creation, Metal Sonic. It is then revealed that Dr. Robotnik had captured Espio in the Combi Catcher. After freeing Espio, Knuckles is then joined by the Chameleon by the Link Rings.
After a small practice demo, the player has to complete all levels, whilst getting comfortable with the new gameplay mechanics, finishing each act, and keeping all of their rings. The Stage cannot end unless the player goes through the Giant ring into the Special Stage at the end of the stage.
When selecting the Training option in the main menu, the player has access to four Isolated Island levels. These levels are greatly different to the ones featured in Scenario mode, but they maintain the same background and textures. All of these levels contain a continuous loop, forcing the player to find an alternate means out of the level. These levels end once the player reaches a strange-looking flower at the end of the stage. In the last level, the player has to find all of the strange-looking plants.
In other media
- The island where the Newtronic High Zone is situated can be seen off in the distance of the stage at its highest elevation.
- Despite being a tutorial stage, some of the levels contain gimmicks not found in any of the following attractions, mainly a water slide.
- A classical version of the island's theme, Door Into Summer, was used for the Collection Room in Sonic Generations.