Knuckles the Echidna in Sonic the Hedgehog 2

Knuckles the Echidna in Sonic the Hedgehog 2 is a platform game released on October 18, 1994, for the Sega Genesis and Sega Mega Drive/Genesis. It results from locking Sonic the Hedgehog 2 onto Sonic & Knuckles through its passthrough port.

This version replaces Sonic with Knuckles as the playable character. Tails is not playable, and the title screen removes the two-player mode and options selections. The game otherwise remains substantially identical to Sonic the Hedgehog 2, with some changes made to better suit Knuckles.

Developed by Sonic Team and published by Sega.