Well, if you're looking for a more fulsome Dungeon Hero experience, you might check out my Fable on Your Table game. It's got some mechanics that are very similar to Dungeon Hero, but it has printable miniatures, a deeper combat system, and a companion web app that procedurally generates dungeons. Dungeon Hero was created as a distillation of that game, so if you're looking to go the other way and get something more detailed and expansive, that's a good pick!
Also, I suppose there's nothing preventing a PDF that has more pages. I just felt that the 'zine size made it nice and portable and kept the play time to nice, enjoyable sessions that never go on too long. But there are people who have expressed interest in making their own Dungeon Hero adventures, so maybe we'll see some new adventures with these kinds of mechanics. (Or maybe you will write some?)