The Japanese version of the game contains an audio drama "Side Story" in the Options menu, unlocked after beating the game on any difficulty, which provides some much-needed expansion on the game's backstory. Working Designs ditched this in the US version in favor of their omnipresent dubbing outtakes, relegating the plot to a summary in the manual. The undubbed audio for the radio drama is still present on the US disc.
The Japanese version of the game is quite easy; a player of average skill can probably beat it on the highest difficulty with a few hours of practice. Unsurprisingly to anyone remotely familiar with them, this didn't sit well with Working Designs. The US version of the game is much, much harder, to the extent that its lowest difficulty is probably harder than the Japanese version's highest one. Enemies do more damage, fewer experience points are awarded, etc. On top of that, the US version renames the lowest difficulty level from "Easy" to "Training", and ends the game after the third stage when playing on this setting.