This was the first Sonic game to be released on multiple platforms (Nintendo GameCube, Sony PlayStation 2 and Microsoft Xbox) simultaneously.
This was originally going to be Sonic Adventure 3 but the team changed the name to Sonic Heroes in a bid to attract new fans to the game franchise.
This is currently the only game where Metal Sonic can speak.
While playing as Shadow or Omega, if you use the first-person camera to look at Rouge, she will occasionally turn her head and wink at you.
Metal Sonic is also voiced by the voice actor for the real Sonic, Ryan Drummond.