Yeah, I noticed this just yesterday when I saw HotFD. It only pertains to Onimusha 3 I believe; the first 2 games based the main character's appearance off another actor (not sure if O1 and O2 use the same guy). I haven't thoroughly played any of them to really know offhand.
As for the movie itself, I enjoyed quite a bit, but more on account of the visual style. After watching a series of independent, artsy movies, a martial arts movie can go a long way. That said, the movie is weak on the story and has a muddled ending of sorts.
Karasu, what's Chungking Express about? I'd venture to look it up myself, save for the fact that I'm on lowly dial-up for the holidays.