Postmortem: "Infernax" (with Hunter Bond and Mike Ducarme)

It's a Nice Postmortem! Hunter Bond and Mike Ducarme talk the making of Infernax—an old school adventure platformer with puzzle elements, unholy curses, and lots of old-school awesomeness. From its earliest conception to playtesting, promoting, and publishing, what did they do and what did they learn?