After Season 1 was totally surprising to me because my expectation of a german TV series was already low, the expectation of a german Mystery TV series was non-existent. But dark delivered. Although I watched S01 just six months ago, I forgot a lot of the plot so I watched some summaries on Youtube. After being clear again about the names and basic relations I was ready to dive into S02.
Season 2 (Spoilers ahead)
Hell. What. Was. That. They introduced two more time(line)s. They introduced the possibility to interact with a future/former self. The future is broken, burned down and even darker. The past is the control center of the all timelines (kind of). It was even more confusing than S01. But: They made the story better to follow since most of the episodes consist of two different characters interact with each other. Or even the same characters from different timelines. While some may see this as a weakness I see S02 as preparation for the the final season S03 where they hopefully tie together all the new loose ends.
dark is great. For a german TV series it is even greater, it is brilliant. I subtract one star for this season because of my fear that the loose ends will not be tied up (looking at you, LOST). If they manage to do so, I cheer Netflix for being able to produce the first german TV series which really was worth watching.