The SNES version of Final Fight some significant differences to the original: there is one less level (the factory level is gone), one less character to choose from (only Haggar and Cody are available) and no multiplayer. There is also a sprite restriction of three enemies at the same time in place.
The goal of this hack is to restore the ability to choose from all 3 characters as well as add the 2 player mode back into the game.