Since Ha Nguyen Dong, 29, created the wildly viral smartphone game Flappy Bird, he said the instant rush of success has driven him to remove it entirely from all online app stores.

Perhaps not ready to let go, sellers on eBay are offering their devices for a steep price because they have Flappy Bird installed. Smartphones and tablets with the game installed are listed at anywhere between $100 and $2,500.

Dong told the Verge last week he was making about $50,000 per day on in-app ads thanks to the game that rules the Apple App Store and Google Play Market. The game simply tasks the user with tapping the screen to keep the bird afloat in the air while navigating an obstacle course. Flappy Bird was just so difficult that users would often be trying their best to top their high score of three.

"The reason Flappy Bird is so popular is that it happens to be something different from mobile games today, and is a really good game to compete against each other," Nguyen told the Verge. "People in the same classroom can play and compete easily because [Flappy Bird] is simple to learn, but you need skill to get a high score."

Dong took to Twitter last week to express his frustration with the whirlwind of attention he was receiving for his game.

"Press people are overrating the success of my games. It is something I never want. Please give me peace," he wrote.

Speculation also spread that Nintendo may have been pressuring Dong with a lawsuit for designing the game's landscape to look like Super Mario World. According to an unverified 9to5Mac report, Nintendo contacted Apple and said the game's artwork was a direct copyright violation.

Nintendo refuted that in a statement to the Wall Street Journal.

"While we usually do not comment on the rumors and speculations, we have already denied the speculation [last week]", Nintendo spokesman Yasuhiro Minagawa said.

Nguyen too said Flappy Bird was not removed due to legal reasons, but indicated online he was highly frustrated with the attention.

He said he will "still make games," but not to ask him to "sell Flappy Bird."