This is an official version of Sonic the Hedgehog 2 with Sonic & Knuckles locked on it. Here, the title character is replaced by his rival, Knuckles, who has his signature ability of gliding carried over to this version. Other than that, the levels are unchanged. If you haven't seen Sonic the Hedgehog 2 completed before, you may wish to do so before seeing what a character with a spindash and gliding can accomplish.

ShiningProdigy9000, Takz15x, and Zurggriff work together to speed through the bonus stages to collect all 7 Chaos Emeralds and zip through the rest of the stages as fast as possible.

For more Knuckles in Sonic 2, we have a run of him just beating the game as fast as possible without having to collect the Chaos Emeralds and a run where he collects nearly every ring in the game. We also have a 100% run with Sonic and Tails instead.

There are also alternate CamHack encodes that attempts to keep Knuckles visible on the screen as much as possible and over any sprite layers.