Arrghh, they did that awful image-distortion thing to stretch it out to letterbox aspect ratio again. Why, why, why?! It looks horrible and stupid that way. Everyone standing left or right of center is bloated out ridiculously. Why would any human being on the entire planet think that was in any way desirable to look at?
Anyway, "Spearhead" is a a better story than I remembered. The production was rather problematical, with pretty bad audio and a rather amateurish look, but the story was effective and the pacing remarkably brisk. Well, in some respects. The downside is that it takes the Doctor nearly half the serial to get his act together and start participating meaningfully in the investigation of the Autons.
I've always found the design of the Nestene life form in the tank, just the pulsing bit we got to see through the window, to be surprisingly effective for something so simple. It's basically just a plastic bag with a rod pulling it in and out in the middle, but it manages to convey a rather creepy pseudo-organic appearance, and it's actually supposed
to look plastic as well, so that works. The rubber tentacles at the end are less effective, I guess because they don't have that disturbingly transparent cell-membrane quality.