A UNIT Story, all but in name.
The War Machines is in my Eyes a bold Statement for Doctor Who going forward. Introducing Ben and Polly, who genuinely bring a fresh new Wind to the Show. They are both played really well by each of their Actors. The same can be said for Hartnell, who feels like he gets an energy boost here, as much as I do like quite a few Stories from before, here he plays the first Doctor with so much energy. It's truly delightful.
Even Jackie Lane's Dodo gets great Material here, ]even if her farewell is non-existing and the very worst of the Show.
The titular War Machines are really enjoyable here, offering us some very nice Set Pieces and great Moments with the Doctor. I especially liked the Moment of that one Cliffhanger where he faces against them. And who can forget WOTAN with its iconic "We must find Doctor Who" Lines?

I don't think it's one of Hartnell's best Serials honestly, while great, I think it would suit the second or third Doctor a bit better if I am being honestly. Still, it's always nice having a Story that gets out of the comfort zone of its Doctor like this one does.