thedkm: Apparently (according to a site), the only difference is the color of blood is green on the Japanese version.
Link here:
http://www.movie-censorship.com/report.php?ID=456266 Regarding the choice of language I can not give you an answer because I never tested the game, but from a screen of the game, it seems that the values of Health and Armor that appears at the bottom of the screen are in English, while messages indicating that the character picks up a weapon or a keycard appears in japanese.
Edit: After test the japanese version,you don't have any choice of language in the main menu,and ingame the text display japanese when you pick up items,like I said the only words in english are "health" and "armor".
That's a bit strange regarding the green blood. You'd think it was the other way around which is one thing I was testing for with the question. At least I have an answer. :) I think the PAL or USA ones would be better in this case then.