This part 2 has a lot of good character moments. Mickey gets to be the one that saves the day (multiple times!) for once, we get a proper introduction for Harriet Jones, and Jackie begins to come to terms with Rose travelling with the Doctor.

The Slitheen manipulate the UN into giving them control of nuclear weapons, which makes it a pretty sophisticated alien invasion. Though I do have to wonder why the claims of the alien mothership being overhead aren't disputed by anyone