The first thing I have to say about this episode is that it's astonishingly strange, seeing an actual episode really titled "Escape to Danger". My generation grew up with the Target novelizations, and Terrance Dicks was notorious for using this as a chapter title in approximately every third book because a) it was a vaguely clever-sounding catchphrase and Terrance loved to recycle anything that sounded good, and b) it was open-ended enough to apply to at least one chapter of every third Doctor Who story. Seeing it used as a real live episode name is like seeing a Star Trek episode called "Beam Me Up, Scotty", or a Buffy episode called "High School Is Hell".
I know it seems like I'm obsessing over a trivial detail, but honestly, there's not much else to talk about in "Escape to Danger" apart from the title. The plot barely moves a millimeter in the half-hour running time, and the Doctor is forced to deliver a lot of boring and meaningless technobabble that's exactly the kind of thing Hartnell does poorly--you can tell when he doesn't really have any idea what the script actually means, because his delivery suddenly becomes stilted and portentious like a parody of a college professor. He's better when he's bluffing the Animus, but there's not enough of the "clash of wills" angle to really give him something to grips with.
Meanwhile, Ian is underused in a way that makes it clear that nobody here is interested in him as a character--William Russell gets to run around a lot and shove men in ant costumes around, and he gets to do a massive (and yet underwritten) infodump scene with Vrestin, and he gets to stare manfully into the middle distance while discussing plans with the Doctor, but he's basically delivering the same generic lines that any square-jawed hero sort would deliver in the same situation. You could give all the same dialogue to Jamie, Steven, Mike Yates or probably Harry Sullivan and nobody would notice.
Oh, and Vicki just stands around looking worried. Any episode where all you give Maureen O'Brien to do is "stand around looking worried" is an episode you have critically failed at as a screenwriter. (Barbara's off this week. Presumably Ian will find her in the Crater of Needles next episode with a good tan.) In short, this is the kind of pedestrian stall that you find in any six-parter, the sort of thing that needs a talented director to rescue it and--oh. Richard Martin. Well, that explains the Zarbi running into the camera and at least two sequences shot so incoherently that you have to rely on secondary sources to figure out what the hell just happened on screen, then.
In short, whenever people complain about 'The Web Planet' being a dull, incoherent runaround with horrible direction and long stretches of tedium, this is probably the episode they're thinking of.