The main menu has a "Collection" section which lists a secret box for all three versions of the game. Complete regular arcade mode with any character, on any difficulty setting. Then, save the game from the options menu to unlock the secret boxes. The secret boxes will turn into the following:
Deluxe versus mode
Complete all three arcade modes (saving after each time), to unlock a new "Deluxe Versus" mode at the main menu. This mode allows a two player versus game using any character from any version of the game against any other character. Example: Ryu from World Warrior up against Ken from the Turbo edition. A handicap may also be selected; up to eight in game speed; number of rounds, stage selection and sound remix.
Sound remix option
Complete each game in arcade mode to unlock a sound remix selection at the bottom of each game's option menu. Turn on this option for "brighter" music and sound effects that are more reminiscent of the Super Street Fighter Series.