I can't believe they would change "Revolution" to "Challenge" in the title for the Europe release.
I can just imagine the panel of "experts" in charge of turning blood green and removing witchcraft references going, "Well, we gotta charge them for SOMETHING!" "Ok, how about we change the name? Revolution... You know. Heads getting cut off and stuff? Oh and make the game 16+!" "Pure genius."
I was disappointed when I played the US version too... Voices are horrible, graphics flicker like crazy, and the controls are just plain shoddy... Doesn't do the series justice... In fact, none of the hajime no ippo games do the series justice... A real shame.