It's Christmas in the 1980s. Adolf Hitler is alive and has two Yuletide wishes: Danger 5 dead... and the world under his Christmas tree.
I'm not sure how I feel about the show making the time jump from the pseudo-60's to the pseudo-80's, since the perpetually drinking/smoking and Thunderbirds-style special effects were so completely and utterly perfect, but the age of big hair, epic shoulder pads, sunglasses, and blazing gun battles where nobody ever gets shot, does have its own stylistic vibe.
And who knows... maybe the series will pull a Black Adder and prove that it doesn't matter which time period you're in, as long as you've got the comedy chops to back it up. (And kill Hitler, of course.)