So much changed..compare the sides of the background where the enemies are standing, the enemies themselves were completely changed too. They changed the background make-up of the scenery (that water wheel -?- went out, and in came a windmill etc.). It's kind of a good illustration of something that was mentioned in one of the previews for HS - that the team just keeps revising things over and over again until they feel they're good enough.
Also, someone mentioned earlier about Nariko having just a few hours to live, and whether that's a reflection on playtime - I just heard from an interview that the idea is that if you fight well, and stylishly, it replenishes your 'life clock'. So there is a caveat there, through the game you'll be able to extend her life (though by the end of the game I'm guessing you won't be able to preserve it going forward..).