I didn't watch the original TV series, but I remember seeing endless commercials for the products. That theme will never leave my head. So when I decided to give the original series a go I started with this. That wasn't the best choice.
The animation is the quality of He Man and the like... less than mediocre. There are a number of songs that are, in most cases pointless and maudlin at best. Many are not well recorded with the vocals and the music poorly mixed and balanced. It's often painful to listen to. And the over-used Hanna-Barbara sound effects would be the arsenic icing on the mud cake.
The script is weak and not well-acted. Often, the film seems like one of Rankin-Bass's poorer efforts. All in all, it's not very good. Not the worst ever, but circling the neighborhood.