Super Mario 64 Sonic Edition is ROMhack/mod of Super Mario 64 that replaces Mario with Sonic, changing the gameplay style to be similar as the gameplay seen in the Sonic Adventure series.
Sonic can run much faster, run over the water and do recognizable techniques such as the Homing Attack, the Spin Dash. When in water, Sonic can't swim, he jumps infinitely instead.
Sonic can also go Super and the player can change the damage system to that of Mario 64 or that of the Sonic series.