I'm not into this kind of game myself, I did try Hearthstone and ended up spending far more than the initial purchase in the short time it took me to get bored.
Regardless, I think this is a great idea and I agree with your assessment above. I've never been much of a FB user but I know a good many people that signed up without any particular interest because "everyone else was doing it". Some of those stuck around long enough to "get it" because the likes of Farmville and similar games that were so prevalent back then and kept them logging in.
This could work for Steem as well but I see one potential difference there that may not exist here as things progress. Everything was integrated, and I don't just mean at the back end, so you couldn't play a game without seeing that someone or other was poking you or liking something.
At the moment if you are a steemit.com user you will tend to come across this additional stuff but that is not guaranteed, depending on the accounts you follow. As people get onto this blockchain via other avenues like this game it is not immediately obvious that all of these services are related. It's early days yet but going forward, I think it will be in the best interest of all involved to nudge people towards also using the other services based on Steem. For example you could implement a simple way to upload a replay of a match as a Dtube video and possibly even share the link to a FB group or something, if that can be done with a couple of clicks, it will be used.
Obviously you need a functioning game first and you have probably already considered this type of thing but it's usually worth keeping things like this in the back of your mind during the design phase.
I'm all in favor of getting talented people out of the corporate rat race and into the blockchain space full time, so I've been voting for you since I read you had done that on a interview with @jerrybanfield if I recall? I will witness vote @yabapmatt now for the same reason.
Am I the only one having a problem getting a witness vote to stick? It appears on the UI but on a refresh it disappears and does not appear on steemdb? It happened to me last week and I assumed I used the wrong key or something on the first attempt...anyway I'll sort it out later, almost late for work :P
I guess I was....worked first time when I got home :/