This movie provides the cleverness of Jim Henson's muppets and a pleasing twist to the classic tale of the Frog Prince. Aunt Taminella puts a spell on Princess Melora so that she can only speak backwards. Even the songs she sings have backwards lyrics.
This movie made such an impression on my youngest child when she watched it at around age 4, and what seemed forever after, that when she turned 19 (the age of Princess Melora when she sang her birthday song), she could still sing this song - and pretty much every other song in the movie.
I rate this movie to be the most well-done of the muppet movies, though probably not the most watched or most advertised. If you can get your hands on a copy from the video store, watch it with your kids. Or just alone!