I've always liked this a lot, although I haven't seen the animation yet. I seem to recall a DWM article years and years arguing it was the most forgotten story. I prefer it to some of Malcolm Hulke's Pertwee stories; it's less preachy, although it has a bit of a "jaw-jaw not war-war" moral in the end. The story flags a bit in the middle, but has a strong start and finish. The last episode in particular seems very Troughton-esque, with the Doctor and his friends bluffing the aliens.

Sam Briggs is still more proactive than Victoria was in her first story!

IIRC, the telesnaps show the model-work to be competent, but not hugely memorable, but it's hard to judge these things from a few still photos.