Sonic & Knuckles, released in 1994 for the Sega Genesis, is a platform game featuring Sonic the Hedgehog and Knuckles the Echidna. It uses unique “lock-on technology” allowing players to connect it with other Sonic games, such as “Sonic the Hedgehog 3,” to create an expanded experience known as “Sonic 3 & Knuckles.” This combination offers additional features like playing as Knuckles in Sonic 3 and accessing exclusive stages. The game’s story follows Sonic and Knuckles as they thwart Dr. Robotnik’s plans to relaunch his Death Egg​