The movie had a few scenes that were just made for the 3-D effect. All that sliding around on the rooftops and gutters and sewer pipes on the ice... pure Hollywood time wasting stuff.
I have read the book 15 times. I bought the CARREY film for my children. If you will give me a day or two, I will watch it again and make a long list. editing this maybe Monday (come now, Christmas is on Sunday..)
Oh yes, there were NO scenes with mice on the floor in the original story.