You should absolutely try! The sausage and bone marrow were my favorites. In this restaurant it wasn't too expensive either, it was quite an average restaurant I think. The frog legs had probably been frozen because a little part of them tasted a little rancid, like frozen fat fish can (or usually) do.

As for the beef tartar, you might want to look it up on Wikipedia, because apparently there's substantial risk of bug contamination which isn't deadly or anything, but might not be something you want. I'll probably only eat that in Norway from now on.