In the Rolling Stone report, Nguyen also talked a little about developing the game. He said he found games like Angry Birds too visually dense, and said he developed Angry Birds as a throwback to an older, simpler era of Nintendo games.
Nguyen took the app down in February citing stress and saying the game was too addictive. At the time, reports suggested that he was earning $50,000 a day from ads being displayed in the app.
For a very simple game which featured such "inspired" visuals and had basically no gameplay, that's pretty impressive.
Of course, the app remains available for people who had already installed it on their phones before Nguyen pulled it off the stores, and he's been earning ad-revenues from those users in the interim. Over time though, this might well have dropped down from the heights of the Flappy Bird phenomenon, but it's safe to say that even in a market that's now littered with clones, Flappy Bird's return would probably be news enough to bring in a whole new set of users.