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 14 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.
Super Hard's level files
The .bin files containing the positions of objects in hexidecimal values placed in the level are located within the game disc and/or PC file system starting with s<stagenumber>_p5.bin (e.g. s12_p5.bin). They can be edited using a hex editor program.
With the help of the tech member on Sonic Retro's thread about object placement, the object's positions and parameters are 0x30 bytes each. An example from that could be 11 00 00 0A. The behavior parameters are assigned to an object in number to tell which action or appearance to commit after the game loads up on Super Hard and normal levels.
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.
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.
The Super Hard Mode screen when the super hard mode has been unlocked.