Magic I've noticed many reviewers here and elsewhere saying things like "worst movie ever", "horrific", etc. Honestly, LIGHTEN UP. If you want to see the worst movie ever, it would be one of a series of bombs by J-Lo for example like Anaconda or Gigi, or anything by David Hasselholf, not this charming, bizarre yet lovable piece of '80s cheese. I once read somewhere that a critic wondered aloud how someone could come up with this plot, even if "everyone was doing handstands in piles of cocaine back then", LOL. Or was that a review of the '80s sci-fi movie Dune? No matter, I can see where it could apply to Xanadu as well.
The reason to watch this movie is for the escapism, the mostly excellent soundtrack and the absolutely mesmerizing Olivia Newton-John. I was in 2nd grade when I first saw this on TV and was completely drawn to Olivia, I credit her for being the first female to make me realize that there was something I liked very much about girls, she was my first crush. She easily convinced me that she could be a goddess, her voice was perfection and she had some of the best songs of her entire career in this film: "Magic", "Suddenly" and "Xanadu".
This movie is loaded with the optimism that was present at the dawn of the '80s, I remember it well, a sort of naivety that had faded forever by the end of the '80s. The opening scene where the muses jump out of the wall is etched in my mind, as is the scene where Olivia skates down the California sidewalk and right into Sonny's life, I remember wishing that could have been me!
It was fun to see Gene Kelly being spry even at his advanced age and playing in a movie that was totally foreign to his era, he was a good sport to even entertain such "young people stuff". He was a sort of father figure in the film, making the other adult characters seem almost like children. Olivia in particular, although already 31 at this time, was as radiant as a teenager.
Sure, there is an abundance of general badness here, but overall, ONJ makes it worthwhile for me. Without her, I wouldn't even bother to review it and probably would have never seen it. But alas, it DOES have her, and some classic tunes with help from ELO.
Don't take this film (or yourself!) too seriously and I think you'll enjoy it.