The feedback from the community and also the press was abysmal for Gothic 3 because the project lacked a lot of time and polish. It was a huge world but it wasn't really filled properly and there were many bugs.
in Risen 1 we had quite an imbalance in the game chapters; as the game went on there was less and less to do, and at the end you had to run through a couple of dungeons. This gave you the feeling that the game became more boring.
What we're doing in Risen 2 is mix it all up: the dungeons will not be at the end of the game but at several points in the game.