While I agree with the previous comment (whereby this series could have been GREAT, if some aspects of the production had been superior), and although I have only recently watched all the episodes via Amazon.com, I was tremendously disappointed with the fact that INVASION was discontinued after the end of Season-1. There was a great deal of potential for the development of additional episodes...
Bearing in mind that I am a major fan of SCI-FI movies & series, I am poised to provide a contribution to these reviews, by placing INVASION among the top 10 science fictions plots I have ever watched. Indeed, because of its unique story line, INVASION WAS truly original, for it is not only unlike any sci-fi story I've seen or read before, but it was also NOT predictable, such as most of the other shows of this genre which I have watched for the past 20 years.
Too bad ABC elected to terminate it.