So the butterfly emits pheromones and makes Iris masturbate on the ground as its attack. The zombie attack added a lot more than what was in the original game, with some added foreplay with some titsucking and cunninglingus.
He also changed how the resist system works. You can't use the old sword icon to gain gauge anymore and then eventually retreat. There are effectively three options now:
1) Resist. It works similarly to how it did last release where it's a QTE to how much of the enemy gauge goes down. You can do this all you want and the bar can even go negative and Iris won't break free, so you can spam it.
2) Guard. I have no idea why you would use this one, as it basically backs up the H scene by one step (if the zombie was in tit sucking mode, it would go back to just him on top of her, for example).
3) Escape. Self-explanatory, if the gauge is empty, you escape. There is something that makes this icon turn into a circle and instead of going back to the battle, it throws you out of the fight and back on the map.
Also there is no spending an item to avoid game over anymore. If you run out of HP it's game over and that's it.