Flappy Bird father Nguyen Ha Dong has provoked curiosity and speculation from his Facebook followers with leaks showing that he is working to bring the smash-hit mobile game back with a new design.

The Vietnamese app developer wowed some 5,600 followers on his Facebook on November 18 by posting a photo, apparently a screen grab of a mobile game, showing four characters, including Faby, the hero of Flappy Bird.

“I’ve done a lot of attempts to make pixel art characters look good and mordern in today world. And I finally stick with this [sic],” Dong captioned the photo in English.

The background of the game features a row of houses and two utility poles with electrical wires, something typical of streets across Vietnam.

One commenter asked below the photo whether the new game would see four players compete against one another, but Dong, apparently jokingly, responded in Vietnamese that he “has no idea.”

On Monday, the Hanoi-based app developer continued to ‘leak’ another screenshot of the game, showing a flying cow against the same background as in the previous photo. Dong only captioned the screen grab #mycowsoft.

Again, the app developer did not reply to any of the curious comments below the photo.

But the leaks have sown hope among diehard fans of Flappy Bird that they will soon be able to play the next generation of the addictive game.

Dong Nguyen, who turned 32 earlier this month, originally released Flappy Bird in May 2013 but only shot to fame in January 2014, when his game topped the Free Apps chart in the U.S. and Chinese App Store. The mobile game, featuring 2D retro style graphics with pixilated characters, ended January as the most downloaded app on the App Store.

In early 2014, Dong said in an interview with The Verge that the game was earning around US$50,000 a day in revenue through in-game advertising.

When the game became a global phenomenon, Dong abruptly pulled it from both the iOS and Android app stores, dismaying fans around the world.

Flappy Bird has since remained being played as a legacy game by those who were lucky enough to install it on their devices before the discontinuation.

However, on September 20, Dong told his Facebook followers that the original Flappy Bird app was no longer playable on newer iOS versions, from iOS 11 onward.

“Thank you very much for your playing and supports in the last 4 years [sic],” he wrote.

In the post-Flappy Bird era, Dong continues to make mobile games through the game studio .GEARS, which he founded in 2012, but none of them have been able to attract as much fame as Flappy Bird.