Vastly shinier production values aside, this was a Monster of the Week, hide-in-a-tunnel adventure, a 1970s scarf and curls throwback. Monument Valley was little more than a handsome backdrop; no organic connection that I could see with the events that unfolded there. The aliens' trick of making you forget them the second you looked away mimicked without improving upon the Weeping Angels of the great Blink episode, which moved when you looked away. (Moffatt recycling Moffatt.)
These days, when there are so many other things one can find to do with any given 43 minutes of one's time, it seems fair to demand a little more nutritional value.
Justified, for instance, is having an amazing season this year, with plots centering on (but by no means confined to) a meth-dealing Ma Barker-style mountain gangster matriarch with three evil sons. The viewing party's complaint about one episode was that it was almost too complicated, with too many interwoven sub-plots to comfortably keep track of. That's what I think in the business world is called a high class problem.