For an involved game with a storyline you might be looking at a more narrow, niche segment of the population. They key is getting them hooked and sharing with friends in their niche.
I can't see the game right now (blocked at work) but you might try posting about the game on some fan pages or community pages that are either related or strongly correlated to the audience you want to target with your game. In a non-spammy way of course ;)