There are a lot of different ideas about game design out there. One thing you see people talk about is whether games should be focused or broad (or somewhere in between). This can apply to many different aspects of the game from the genre to the system to the goal of play. Some folks believe that games can only do one thing really well and the more you try to add the more that diminishes the game's quality. I personally do not believe this. I think there is a place for focused design and I think it has value, but I also think most groups do not consist of players who all agree 100% on a narrow set of preferences. I've seen this at my own table and through the customers of our products. There is nothing wrong with narrow design and there is nothing wrong with broad design but both do have consequences worth considering and these days I have moved from more a more focused approach to a middle approach that avoids either extreme.
Let me give an example with one of our own games: Crime Network. It is, in my opinion, a wonderful system. It is also very focused on a narrow type of setting, one where the player characters are all members of the mafia. This is narrow in terms of concept. But the mechanics also feed into that. I think in hindsight we could have, and should have, made the mechanics even more focused on mafia material. One aspect of the game we decided was missing after it was released was it ought to have had a higher level of lethality than other Network products. Or I should say, a particular kind of lethality: making the one shot kill easy to pull off. But on the whole this was a game built around the idea of playing mobsters and I think we did a pretty good job.
That said, how many people are really going to buy such a game? And out of the folks who buy it, how many people are going to run campaigns regularly for the rest of their gaming days? Even in my own group, while everyone had a blast playing, it wasn't something I could run constantly. It was more of a game for special occasions and seemed to work best in 2-4 month long campaigns.
Many of our early designs were quite focused. I like focused games. I think they are a lot of fun. But I also like games with broader appeal and I also am interested in designing to the realities of the table these days. The reality is, it is somewhat rare to have a group of players who are all on board for this sort of off-beat concept. I happen to know several such players and when we play Crime Network or a similarly focused game it is great. But it is much easier to recruit gamers if you are starting with a more broad concept.
At the same time, when you get too broad with a game, it becomes quite vanilla. Sometimes that is good. Vanilla is a popular flavor of ice cream for a reason. Not only is it something most people find they can stomach but it works great as a base for more complex flavors. With games it is the same way. You can take a game that is quite broad and use it for many different kinds of campaigns. That said, I am not terribly interested in making something broad or generic. I do like my games to have a certain amount of flavor attached to them.
Narrowness can also be about design philosophy. Whether that be one of simplicity or one of agendas. And again I think here, for me it is much easier to avoid this and just look at what people are really after at the table. Players have a stubborn habit of being all over the map in this respect. It is easy to come up with a overarching idea of design that sounds good and wins arguments on the internet, but much less easy to make a uniform theory hold over actual playgroups. People are just too diverse and their tastes too personal. So now I've chucked all that. I don't worry about it. I just worry about what happens at the table, what people like, what they want, what makes the game work for them. Perhaps most importantly: what works for me as a GM and Player.
This isn't a rejection of how we designed things in the past. I am proud of Crime Network and our other early games. It is just an explanation of our development, how we went from narrow and light to where we are now. It also isn't a statement that we will never do another highly focused game. We well may. But If we do, it will be with the understanding that with greater focus, the more narrow our audience and the more game may be suited for special occasions.