Unfortunately, the fact that we've been here before means that all the plot beats that are wholesale swiped from the first story are immensely tedious in this one. Making Ortron just as mistrustful of aliens and the Federation (despite an early effort to suggest otherwise -- "Right from the day Chancellor Hepesh died, I served your father loyally. I worked for the things he believed in. Progress, civilization, the Federation. Now there is war with Galaxy Five and our people have to make sacrifices. ... We have to accept the duties of Federation membership, as well as the benefits") is frustrating to watch, particularly since he doesn't have a particularly good motivation for doing so; there's a suggestion that he thinks the Doctor and Sarah are responsible for sabotage and/or murder, but this seems to have been dropped as a motivation by part two. Instead he's just treading in his predecessor Hepesh's footsteps, acting as an antagonist because that's what the story needs.
This might be bearable if the new part of the plot (all the mining stuff) was handled with suitable care, but most of the miners are treated as warmongering boors, and thus it's difficult to feel any sympathy for them. Well, to be fair, Ettis is deliberately written as a hothead, in contrast to the cooler approach of the miners' ostensible leader Gebek, but that doesn't explain why all the other miners seem to agree with whoever happens to be speaking at any given moment. Really, the whole thing feels designed to lurch from one crisis to the next, with little thought as to the cumulative effect on the characters. Like Ortron, the miners behave however the script needs them to behave at any given moment.
Are there any bright spots in these two episodes? A few; Nina Thomas does a decent job as Queen Thalira, even if the script requires her to be naïve and largely helpless, and Donald Gee's performance as Eckersley is the right side of concerned yet superior (and miles ahead of his performance in The Space Pirates -- unless video of that shows up to vindicate him). Elisabeth Sladen continues to excel as Sarah -- her reactions in the throne room are particularly entertaining. There's that first cliffhanger, as the Doctor mouths/speaks (depending on which version you're watching82) "What the blazes is it?" when confronted with a giant glowing image of Aggedor. And Alpha Centauri is as wonderful as ever. But that's really it. These two episodes are an unexciting muddle; let's hope things improve.
82 They brought Pertwee's line up slightly in the mix on the DVD -- presumably so people didn't think he was mouthing something ruder.