I just had my first interview for a Phd position in Germany via video call. And I am not sure whether interviews in Germany are always like this and therefore I don't know how to feel about it.

To the interview : it was two hours long. I was interviewed by the leading professor and another professor. And I was only asked to talk for about 15 mins about my master thesis , which happens to be very related to the research field there. And then the professor went on to talk about a possible research project. And after one hour or even less the leading professor left and then the other professor just talked straight for one hour about the university , I did not say much at all , just asked four to five questions.

I asked him when can I expect an answer and he said in two weeks I will get an answer for sure.

I really did not expect the interview to be like this, i don't know what impression I have left .. anyone with a similar experience ?

Sounds similar to mine for UK universities, only I think the interviews were only 30-45 minutes long, thankfully! Even though I rambled off topic for one, I still got an offer, so you probably did fine. The most important part is matching your research aims to the department strengths, which they have decided anyway by looking at your proposal/prior research paths.

Seems pretty normal, just longer than usual.