Story: 4/5 - Extras: 5/5
As I understand it, some people love writer Eric Saward's "Earthshock" and some hate it. Just to be awkward, I'm going to say that I like it, but it's not perfect.
Earthshock carries with it a bleak atmosphere not uncommon in the Peter Davison era alongside such stories as Resurrection of the Daleks and The Caves of Androzani, particularly in the death-heavy first episode, with which its sequences of caves and androids is actually a massive diversion from the real enemies - the Cybermen - who only appear at the episode's climax. I imagine that if I was watching Doctor Who in the early 1980s I'd have been pretty impressed with the revelation.
I've never found 1980s Cybermen particularly menacing, but there's no doubt that in Earthshock they do have a certain edge that they would subsequently lack in stories such as The Five Doctors. In Earthshock they really are a powerful force, breaking out of their hibernation silos in droves, murdering anybody who stands in their way and getting up to a fair amount of scheming, too. The voices may not be as chilling as they were in the late 1960s, but they're more intelligible, and it does allow the Cyber Leader to have better lines.
Other aspects are less successful. The numerous supporting characters introduced in episode one, such as Lt. Scott and his troops, become somewhat redundant once the story switches location to a space freighter in episode two (and picks up its new supporting characters in the form of the freighter's crew), none more so than Professor Kyle, the leader of the archaeological expedition, who spends the rest of the story hanging around with Nyssa in the TARDIS until she eventually gets shot. Like many stories of this era, there are too many companions - but that, of course, is all about to change.
Weaknesses notwithstanding, the plot of the story is well constructed and there's a dramatic send-off for Adric as the TARDIS crew is reduced in number by one.
Earthshock comes with a strong package of extras, including a chaotic commentary with the full TARDIS crew, a thirty minute documentary on the making of the story with numerous leading contributors, the usual on-screen production notes, a few film trimmings and bits and bobs from the TV archives, and informative on-screen production notes. Excellent.