Like the previous reviewer said, the animation has been done on a shoestring budget, but it is based on the original comic artwork of Jack Kirby. The stories are also ripped directly out of the sixties comic books, being fun if simplistic tales featuring all the Cap's main adversaries.
Maybe it's because I used to watch and enjoy these as a child that accounts for my opinion of them, they are very old fashioned and the cover art is very misleading. On the plus side, all episodes are included in one 2 disc package, unlike the previous (partial) episodic releases.
In short, if you know what it is you'll probably enjoy them, if not you'll no doubt be disappointed. Very cheap, very retro kitsch, but very cool and collectable.