User:TheJoebro64/Hidden Palace Zone

Hidden Palace Zone is a scrapped level intended for use in the 1992 video game Sonic the Hedgehog 2. Set in an underground cave, the stage was planned to be where the player was granted the ability to turn into Super Sonic. Hidden Palace is considered somewhat infamous among the Sonic 2 levels for its widespread appearance in gaming magazines and promotional material before being cut from the final game.

Sonic the Hedgehog 2
Hidden Palace was originally planned to be a stage in Sonic the Hedgehog 2. According to series creator Yuji Naka, the stage was intended to be accessed by collecting all the Chaos Emeralds, and upon completion, players would be given the ability to transform into "Super Sonic", a bonus mode in which Sonic has increased speed and invincibility (the ability is given to the player automatically in the final game). The stage was kept in the game for most of Sonic 2's development cycle, being removed a mere two months before the game's release.

Sonic & Knuckles
A stage known as "Hidden Palace" appears towards the end of Sonic & Knuckles, however, it is vastly different from the Sonic 2 stage, as it serves as the location of the Master Emerald.

In Sonic's campaign, Sonic reaches the level after completing Lava Reef, the prior level. He has a brief confrontation with Knuckles the Echidna, after which Sonic defeats Knuckles. While the fight occurs, Dr. Robotnik steals the Emerald, electrocuting Knuckles when he tries to stop him. Knuckles then guides Sonic to the Sky Sanctuary to chase Robotnik.

In Knuckles' campaign, Hidden Palace plays no major role, simply being used as a transition point to the final boss.