The series narrates the stories of somewhat ordinary people as aliens start an 'invasion' of Earth.
It is not an action movie, and as such it is in no hurry to show big explosions and close a single main plot. And that part is quite refreshing.
I do hope that the story unfolds in future seasons and the creator's ideas of what the aliens are, how or why they got here, and how humans 'move on' from this encounter are captured.