There are definitely some issues with the portrayals of the Aboriginal, Chinese, and Maya characters in relation to the Greek one, and parts of the first half drag on a bit, but it is a good story. Adric's characterization is a little sudden but good for his character, I think: he's been through so much and feels picked on and neglected, so it makes sense that he would fall for the premise of a perfect future with someone taking care of everyone. It illustrates the temptation of such a system. Tegan's characterization is really good, too: she's stuck being the only responsible adult on the tardis, her concerns and valid fears are brushed off as silly, and unlike the others she has a home and normality she still wants to get back to. It makes perfect sense that she freaks out and tries to take it into her own hands and just tries to leave in the tardis. And she actually sort of succeeds through determination and reading the manual!

I like the general message of anti-eugenics, of "perfecting" humanity being both unethical and incorrect as an ideal. And the ending where the dictator was shown to allow himself the same thing (fleshtime) that he convinced his followers they were better for no longer having was a good show of hypocrisy.

Also I enjoy the Doctor using a cricket ball to propel himself through space.