I'm hesitant writing a review as there are so many long reviews, giving extremely in-depth interpretations of this film. Most of us just want to watch a film, then decide whether we like/hate it! We shouldn't have to analyse the story, and work out hidden meanings, and highbrow subtleties.
Some reviews point to the couple going to the estate agents, looking for a house as the pointless part of mundane life! Being young, having children, growing old, then dying! I mean, there is joy in life too!
It wasn't a satisfactory ending, I mean, if the hidden meaning was the depressed writer telling us we all live pointless lives from cradle to grave, should then realise the aliens had completely and utterly pointless lives. Tricking a couple to visit a huge housing estate they couldn't then escape from, why would aliens prefer their own pointless lives?
The alien boy was well acted, but I must admit I wanted them to kill him! Suppose that wouldn't have worked, another baby would have been delivered! Disappointing ending!