Some parts, you kind of have to suspend disbelief - like shia lebouf swinging around the trees, which seemed mildly out of place.
It was a bit sci-fi for my liking in an adventure movie, but I can see where they made it work.
Overall, it was a very good movie on it's own. As part of the "indy" series of movies, it really falls short, because I felt that the cleverness that made the other Indiana Jones movies classics was severely lacking. But on its own merits, it's pretty good.