In addition to media pressure on his personal life, Nguyen felt that Flappy Bird was too addictive for a lot of players. After receiving a few emails from people claiming to have lost their jobs because they kept playing Flappy Bird, he decided to take the game down for good.
Taking the game off the app stores didn't stop the money streams from in-game ads of already-installed copies though. This allowed Nguyen to quit his day job and focus on developing other mobile games. He is currently working on several titles, including an action chess game called Checkonaut and a flying game called Kitty Jetpack.
At the moment, Nguyen isn't really sure whether he'll keep Flappy Bird of the stores forever, but he's sure that if it ever does become available again, it will come with a warning: "Please take a break."