Yeah, I know, I just hit "publish"... But there's so much to do still! You may have rolled up your mighty hero using the Stygian Citadel Player Guide, and now find that they don't have much to do. Where are the maddening ruins and terrible phantasms? Why, they're coming up in the first supplement to the game, the Adventure Guide! (Unless you as a GM want to come up with your own stuff, which is cool, of course.)

The Adventure Guide should have a roster of opponents for your hero to fight, traps for them to avoid, and of course, treasures to collect. But more than that, I mean for it to be an adventure generator for use in solo or GM-less co-op play. 

Then, after that, I'm looking at a "Campaign Workshop" (name still in the works) with random name tables and other things to fill your campaign world with, if you're stuck for inspiration. Those three files (one page each of course) should be enough for most games, but I'm already eyeing some advanced rules in a potential fourth leaflet. From then on, who knows?