I wanted to like this, I truly did. There was quite a bit of fun dialogue. Orson Welles' reading of The War of the Worlds could have made for an excellent Who story, full of atmosphere and just a dash of horror.
This is not that story. Instead, Gatiss throws everything but the kitchen sink into the plot. It's as if he pulled out an encyclopedia and made a list. America in the 30's:
Bad accents? Check.
Throw in some Martians-who-are-not Martians, a completely stereotypical villain, and mix.
McGann and Fisher do what they can, as always, with what they've got, but it just isn't enough to save the dismal plot.