Hi Hi Hi/C Moon was a good single - in an era where the single was starting its death agony. The A side was nice and rocky, in a typical Paul/Wings way: you know, designed to be not too in-your-face. (That's probably what PC31 refers to with his "bubblegum" remark.) It's also about sex, in a nice sort of way. You could play the record to your mum, and she'd only blush at most when the nice bit of "fast and jerky" music came on near the end.
The B-side is different and quirky enough to provide a nice and welcome break from playing the A-side over and over.
Did I say a good single - it's a GREAT single!