The series is amazing. One of my fav ever. This was far short of the series and mostly because Harry isnt Harry at the start. Yes Ruth is dead and he is different, but there are some character traits that set the whole thing in motion that Harry wouldnt have done. Anyway, for a series that had such great writing and tension, this could have been so much better. Still... I'd watch a sequel.
The TV-series-to-film leap is partially redeemed by a final line critiquing the Stasi's hyper-surveillance dystopia. Otherwise, this could have easily become a mouthpiece for gov propaganda seeking to curtail liberty under the 'nothing to hide, nothing to fear'/'for the greater good', authoritarian, guilt by association paradigm. Tech-tropes, character arcs and dramatic developments are competent if little more.