Been There, Done That
'The Return of Zarrko, the Tomorrow Man!' is a pretty formula story - once again Loki, unable to go to Earth himself, finds a proxy - this time, Zarrko - to battle and bedevil Thor. The only twist this time is that Thor, under punishment from Odin, has only half his power.
Then there's the requisite and unremarkable text story and sci-fi comic backups, but they hardly bear mentioning.
Finally, we get another 'Tale of Asgard'. This time subtitled, 'The Invasion of Asgard'. I've come to realize that it's best to regard these Tales of Asgard as apocryphal tales - legends about a legendary figure. In this one young Thor, still not even capable of lifting Mjolnir, manages to hold of The Forces of Evil (yes, all of them) from invading Asgard - single-handedly! It's really not as bad as it sounds, but lacks a sense of 'realism' at least comic book realism circa the 1960s anyway - but it's enjoyable enough as a backup story.
Overall, this issue feels very familiar, rote even, but it has just enough going for it to make it worthwhile for Thor fans, but probably no one else.