Super Hard Mode is a single-player mode of gameplay in Sonic Heroes that is unlocked after achieving an A Rank for every mission in the game.
In Super Hard Mode, the player traverses through all fourteen stages of the game but their level layouts as well as the types of enemies have been tweaked to make this mode difficult to complete. The game saves after every stage in this mode and allows the player to resume the last stage reached by the player during gameplay. There are no specific missions in this mode other than reaching the Goal Ring, thus allowing the player to take their time as no Ranks are given. Only Team Sonic is playable in Super Hard Mode, but this mode is not considered part of their gameplay. Notably, comical elements are added to the Stages in Super Hard Mode such as seagulls in Seaside Hill and an extra teleporter for the Giant spiderweb room exit from the third core room in Mystic Mansion.
The tutorial stage doesn't have the texture and animation files available for Super Hard mode, instead will just load on black with the spinning frames. It can be accessed through the memory editor.
The special stages can be used with the Action Replay code provided for the game that will directly jump to these if the player presses the L+R+X buttons during the completion scene at the goal ring or if the special stage keys haven't been deleted from the stage. However, it will be impossible to enter boss levels with those since Super Hard Mode doesn't have boss nor special/emerald stages.
Actually, while the Hint Ring are all deleted from the mode, one has been used for the cage spotted near the mushroom in Frog Forest which was included from the regular Team bin files, though most likely an error.
As of the Gamecube prototype 10.8 version of the game, it does not have the stage P5.bin files present on disc and will not be playable all the way through to the end unless the disc image with PB.bin files have been replaced. After not pressing start, the title screen will redirect to the gameplay in Super Hard mode with Sonic and friends moving around and not going anywhere else on Seaside Hill.
A beta Super Hard selection screen in the prototype 10.8 version of Sonic Heroes.
Sonic, Tails and Knuckles moving around in one area of Seaside Hill on the prototype recorded gameplay.
The Super Hard Mode screen when the super hard mode has been unlocked.