The sound Freddie makes when defeated was changed in the international version of the game.
There are two Street Fighter characters that can be seen in some of the stage backgrounds. Guile appears during the boss fight with Freddie in France, and Chun-Li appears in the first stage, where she can be seen eating ramen.
Won Won wields a meat cleaver in the Japanese version of Final Fight 2, but this was removed in the English version. Despite this, the artwork featured in the manual still has him holding the cleaver, and the text warns to "be careful not to get too close to him or he'll slice you up". While no official explanation for the change has been given, it was likely due to Nintendo's censorship policy, since characters could bleed when hit by it.
Similar to Poison and Roxy in the original Final Fight game, Mary and Eliza were replaced by male characters called Robert and Leon in the international release.