"...an amazing tale of getting to the number one spot on the Apple App Store! The app in question is called A Dark Room, a simple text-based game with an awesome story and experience. Originally a web game, Amir helped build an iOS version of the game. The conversation then digs into all the subtle things done in the game to help encourage players to promote it - when to ask for a review, when to put the game on sale, the impact of magazine reviews of the game, and more!"
A Dark Room (web game)
A Dark Room on the App Store on iTunes (iOS app, $0.99)
The author is a bit surprised of success of the app.
There is a possible simple explanation: the game gets the user in the "flow": it is not easy, but it can be handled, and it is getting progressively harder, challenging enough to keep interest but not too much to give up.
The author highlighted one crucial element of "viral success" asking for feedback (review) immediately when the user succeeds. That is the best time to get a positive review, and many of them, and that prompts the app ranking in the app store.
He did mention that despite great app success, the income from it is still less that he was making as a consultant.