In an interview with Forbes that took place in Vietnam, Nguyen said he shut down Flappy Bird because it became "addictive." It was also causing him a lot of stress.
"Flappy Bird was designed to play in a few minutes when you are relaxed," Nguyen told Forbes reporter Lan Anh Nguyen. "But it happened to become an addictive product. I think it has become a problem. To solve that problem, it's best to take down Flappy Bird. It's gone forever."
The Forbes reporter noted that the 29-year-old game maker looked "stressed" and smoked a number of cigarettes during the interview, which was less than one hour long.
Nguyen also said the app was disturbing his personal life. Forbes says he yanked the app due to "guilt."
"My life has not been as comfortable as I was before," Nguyen said. "I couldn't sleep." He plans to make more games and leave his other two hits, Super Ball Juggling and Shuriken Block, in app stores. But if players get too addicted, Nguyen says he'll yank those too.
What will Nguyen's next game be? That isn't clear, although the Forbes reporter caught Nguyen doodling monkeys.