Yeah, I know it's not confusing altogether, but I've seen enough games where you have the mixing so great that the same words will occasionally have both spellings. This works out okay if you have characters with a different accent but being American I've heard enough people complaining about these things. As I said, I think the British-style is better for this kind of game anyway (the only ones where I think it doesn't really fit is if you have a game based in America i.e. Al Emmo) but if you're required to use one form, then it's good to keep vigilant.