Untypical for Hitchcock in that the plot does not involve any crime at all. I don't know whether that would disappoint other viewers or not, but for me, it was a delightful surprise. Always good to have a change-of-pace, and in this case it works wonderfully, especially with using Billy Mumy who was even younger than when he appeared in the "Lost In Space" TV-series.
To put my feelings in a nutshell, what I'm really trying to say is that the episode's ending is actually HEART-WARMING!!