Smart comedy marred by ham-fisted ideology at the end
I thought the first half or so of this film was really brilliant satire, a twisted version of the comedy trope of the straight man and the comedic foil. Hitler was played with great subtlety as the straight man, being "Hitler" without being the cartoon version most commonly seen in Western media or the dark psychopath type like Bruno Ganz's version in "Downfall".
The man-in-the-street types played in the first half were the comic foils, with the whole thing feeling like a more realistic version of Sacha Baron Cohen's "Ali G" characters when he plays them so straight that the humor is in the unstaged reaction of the innocent man on the street who isn't in on the joke and doesn't realize that his straight reactions are what's funny, not the obvious character's behavior.
After about 1/2 or 2/3rds of the way through this film, though, it seemed to get too caught up in it's morality play about the careerist TV executive and his collapse after seizing power. That was too much of an obvious parallel to Hitler's career himself -- the TV executive in his office was Hitler in his bunker, explaining how he would stop the Russians only to be told his army had collapsed.
The very end with the news footage of anti-immigrant protests just seemed ham-fisted, as if the audience had to be told what its message was. All of the irony and humor in the first half was evaporated by then and we were just being beat over the head with another screed.
Far better would have been continuing the straight man routine, with Hitler's bizarre but accurate critiques of modern Germany turning its political conceits on their heads. The bit about Hitler respecting the Greens for their environmentalism was genius.