"Flappy Bird" has flown the coop.
The addictive game that soared to the top of iPhone and Android app downloads disappeared from app stores on Sunday, though players who already have it apparently can keep on flying.
A tweet from the game's creator suggested that its sudden success had become an albatross.
"I am sorry 'Flappy Bird' users, 22 hours from now, I will take 'Flappy Bird' down," developer Dong Nguyen wrote on Saturday. "I cannot take this anymore."
Nguyen, a Vietnamese developer with a studio called DotGears, did not reply to CNN's request for an interview last week and has stayed mostly quiet in the wake of the game's recent and sudden success.
His no-frills game gave players a chance to steer a tiny bird through an obstacle course of metal pipes. But it's unclear why it shot to the top of the most downloaded charts.
Although new players can no longer download "Flappy Bird," the game remains playable for those who had already added it to their devices.
Hundreds of phones with "Flappy Bird" installed have suddenly appeared for sale on eBay at prices up to $15,000.
"Flappy Bird" was originally released for the iPhone in May but didn't become the top free iPhone app until mid-January, following a surge in popularity that seems to have kicked off in early December. Observers have voiced several unproven theories about the game's sudden success, including the use of bots to get it on Top 10 lists artificially, organic enthusiasm on social media and a surge in amusing user reviews in the Apple App and Google Play stores.
Nguyen told Chocolate Lab Apps he created the game in two to three days and says he did not promote the app in any way after its release.
In a series of Twitter posts Saturday, he said he wouldn't sell "Flappy Bird" and would continue to make games.
"It is not anything related to legal issues," he said. "I just cannot keep it anymore."
Last week, "Flappy Bird" had an average four-star rating from more than 543,000 reviews in the Apple App Store and 228,000 on Android. Many of the reviews were lengthy, tongue-in-cheek tales of time lost, marriages ended and people going cuckoo after playing the game.
CNN's Heather Kelly, Nick Valencia and Maegan Ahern contributed to this report.