I watched half of this with my five year old and I thought the whole idea of the Whos' world being destroyed was a little dark and heavy for a preschooler (although I know it all ends happily). I also didn't see the point of featuring a dental office with horrible screams of pain, big needles etc. I also thought it odd that when the movie's villian, a scary, bone-knawing vulture, asked the mother kangaroo for her child in payment for going after Horton, she said she was considering it. I understand that way they slip dark humor geared towards adults into this type of movie to keep parents interested, but it has to be very subtly and carefully done. A preschooler that catches this comment won't get any humor out of it--only a dose of confusing darkness.