Mafia 1 was a very good game, but it's not right to compare it to GTA games. I was playing both around that time, and despite superficial similarities, they are very different. Mafia had excellent combat (first game I remember where enemies would dodge behind objects during gun fights) and a very good story by video game standards. But its large open world was just a background for driving from mission to mission. Unlike the GTA worlds, which were filled to the brim with stuff to do, after you completed Mafia missions, there was nothing else to do.
In a way, it didn't matter, because they were going for a more story driven game, but I couldn't help but feel some disappointment after finishing it, wishing there was more stuff to do around the virtual city. I certainly hope that with KCD, they will put in more effort into fleshing out the world and making it more sandboxy. I do think that with things like advanced NPC scripts, wildlife and some of these mini-games, they are on the right track.
