This hack replaces Sonic with Knuckles, significantly altering the gameplay. Knuckles' abilities differ from Sonic's, particularly his climbing and gliding, which would change level traversal strategies. The core platforming remains, but the experience is fundamentally different thanks to the character change. This shows the creativity of the modding community and the scope for character-driven gameplay alterations.

Sonic the Hedgehog (USA, Europe) [Hack by Stealth Rev 1] (~Knuckles the Echidna in Sonic the Hedgehog)

Sonic the Hedgehog (USA, Europe) [Hack by LOst v1.0] (Sonic Jam's Easy Mode)