This was a perfectly fair follow-on from the gripping original. The opening sequence with the arrival of the aliens was particularly cinematically effective and we then went to virtually the follow-on from the final shot of the first film. The aliens were more clearly and explicitly shown (which did not make them any more frightening or add a great deal to the story) but the story, necessarily I suppose, had to have several strands and new characters to allow development, most significantly the separation of the family in order to continue. The intensity of the first film, with its gripping and exclusive focus on the family was missing, as was the development of their skills is learning to live in a new and very dangerous environment.
I gather a third one is planned, so it will be interesting to see in what direction it is taken. We will see.