Well, that is the problem with stories such as that. I heard it as a child. I told it to my kids. So, the story is familiar. There was a lot added to it that was not out of line or wrecked the familiarity. This movie gives a little more substance to the magic beans with some back story I don't remember from tales I've heard. Jack doesn't go alone up the beanstalk and he has more reason to go than just to climb the thing and see what is there. He also seems a bit daft at first but turns out to be fairly clever and quite brave. I liked that. Not a lot I can say without giving the story away.
The reviews I've seen are mixed. One organization declared the movie bombed. Plus, it is only getting 3.5 stars. I'd give it at least a 4. It is visually very good in Imax 3D. I'd have given it a higher rating except it is not original.
Keep in mind, I liked John Carter and the industry panned the heck out of it. I also liked the last Twilight movie and the critics gave it all kinds of razzie awards. Maybe I am not the audience the critics review movies for.