Sonic 3 & Knuckles Download PC

Sonic the Hedgehog 3 and Sonic & Knuckles were intended to be a single game, but were released separately due to time and financial constraints. The Sonic & Knuckles cartridge features a "lock-on" adapter that allows other Genesis cartridges to be physically attached to it. Connecting the Sonic 3 cartridge creates a combined game, Sonic 3 & Knuckles. The lock-on function is available in some rereleases, such as the Virtual Console service for the Wii.

Sonic the Hedgehog 3 & Knuckles allows the player to play Sonic 3 levels as Knuckles or Sonic & Knuckles levels as Tails or both Sonic and Tails. Other new features are the ability to collect Super Emeralds, unlocking new "Hyper" forms for Sonic and Knuckles and a "Super" form for Tails, improved save options, access to new areas that Sonic or Tails could not previously access, altered boss forms, and an additional ending that shows Sonic returning the Master Emerald to Angel Island.