Nope, these aren't 80's mix tapes, these are games.
I've been having fairly good luck with eBay lately where Commodore 64 games are concerned. Here we have a lot of ten datassette games for which I paid just under $15, counting the extra shipping I had to pay due to the seller underestimating the package's weight. Bad form, eBay seller.
Anyway, the games are On Field Football, Lazy Jones, Super Skramble!, Yie Ar Kung-fu, Pitstop II, Scalextric, Forbidden Forest, Mind Games American Football, Softaid: Feed The World (A charity compilation by the Band-Aid Trust), and Frank Bruno's Boxing.
I'm stoked about the whole set, but Forbidden Forest in particular, as it's another of the games I grew up with. Also, the 'Feed The World' tape is intriguing because of the history, if nothing else.
Now, I just hope these tapes are all still working.