Why anybody would attack through a choke point like that canyon. I suppose all military science disappeared along with the concept of hand thrown HE? It would have been easier to suspend disbelief if the village had been shown to be down in a crater with only one way in.
Also, did everyone omit to say what was being mined?
On the other hand, the framing shots were imaginative, with great effect.
And if Fionnula Flanagan's Magic Kazoo is about killing off all the aliens, then the hint of a continuing storyline actually addresses the theme of racial tolerance/racial war.