Well, this certainly is an interesting one, in that it feels like an episode of a completely unrelated drama series with the Tardis team superimposed over it, with their main mission being to save themselves more so than the people around. It seems a story born out of convenience more than anything else, like it was made because they had some big props lying around in the drama department, which has a certain scrappy charm to it, and if done correctly, can and has worked marvellously, here it just works decently well.
It really not bad at all, perhaps just unexceptional story-wise, it does have some problems like some messy writing, blocking (in the first part), acting and directing here and there, but largely it is good. If you are as Classic pilled as I am by now, there is definitely fun to be had, with a good Tardis team, good vibes and some good acting from Jacqueline Hill, especially in the second part.
While the story is a bit unexceptional, I will say, from a technical perspective it is quite interesting, using projectors, inserted pre-filmed clips, superimposed video, a shrinking effect and some quite inventive set designs like the giant sink set, this is all very impressive for being made in 1964 and on a shoestring budget.
7/10