If you choose to fly to Germany with a certain orange-tinged budget carrier, you shouldn't be surprised to end up in Berlin when you booked Hamburg. Or in Hamburg when you booked Dortmund. Because the map of Germany that this company uses (at least in their ads, hopefully not for their pilots!) looks like this:
Four cities are definitely wrong, one may be right (hard to tell as Dusseldorf and Cologne are so close to each other, so the line indicating Cologne may be pointing to either), and Munich appears to be vaguely in the right area). I recommend to take the train instead.