It's not just by comparison that this episode looks weak. Coming off of such a high point, it was probably inevitable that a clinker would sneak in. This would not have had to have been a clinker, but certainly is.
Where Fontana was subtle and wise, Roddenberry is clunky and preachy. Again the Prime Directive is trotted out, and again it fails as a dramatic device. This is a problem because the concept seems very dear to the writer. So why then, we might ask, do the characters continuously bring it up and then break it? If this is, in fact, your "prime directive" -- that is, the first and foremost principle you are taught to follow in Star Fleet -- why is it even up for discussion?
The reason is clear. Though it's a social concept important to Roddenberry, it is a killer to the drama. If your characters are to follow this, they simply wouldn't beam down anywhere. There's just too much risk. So the inner turmoil in this episode is not what the writer wants it to be (Kirk and McCoy sparring over whether to help the natives), but between what the writer WANTS to do (preach), and what he NEEDS to do (tell a story). It's a lesson to would-be writers: don't hobble your plot with garbage like this. Just tell your story. If you do it right, and create characters and motivations carefully (see Fontana) you can address any issue you choose without hobbling your plot.
It's not the only problem with the episode. The aliens really look terrible. The wigs are horribly big and obvious, and the whole thing has just a little too much "flower children" sensibility (this problem is going to get worse before it gets better). And the guest star as Nona is no match for the more formidable guests we have just seen. In fact, she's quite over the top. And what's with those pants? Star Trek costumes are rather hit or miss during this period.
Then there is the illness device. In this episode both Spock and McCoy get shot (each suffering invisible wounds with instantly dry blood stains), and Kirk is savaged by a man in a monster suit. The guest star gets knifed to death, and we have a new doctor brought on board just to bitch-slap Spock back to life. Fontana showed that illness need not suck the life out of an episode, but Roddenberry doesn't have the same skill. With everyone laid up at one time or another, we might as well be watching a show about a medical ship. As a device, here is it misused.
Even more problematic is the staging of several scenes. In the opening we are asked to believe that Kirk and Spock -- in their brightly-colored uniform shirts and black pants -- are not visible to the planet's inhabitants. The camera angles are particularly unfortunate. This continues to be a problem throughout the episode.
There are some nice lines, and a nice central concept about balance of weaponry, which was a hot topic when the show originally aired. Roddenberry shows his pessimism by the knowledge of the future he gives to his characters. Kirk seems hopeful, but the ambiguous ending is completely unsatisfying. Did Kirk rescind his order for guns? Being philosophical is one thing, but Star Trek usually isn't this sloppy. The story really has no end. And while it could be argued that this was intentional, I think more likely was the need to wrap things up, and a desire not to get too overtly political. The series wasn't usually this cowardly.
Rating: Middle (4)