2048, a simple puzzle game first released as a browser game in early March, has become a cultural phenomenon, following Flappy Bird into the annals of flash-in-the-pan gaming hits.

But 2048 is a clone – in fact, a clone of a clone of a clone – and the makers of Threes, the original game on which the original clone is based, have finally spoken out about being ripped off, saying that "Threes is the reason 2048 exists."

"We do believe imitation is the greatest form of flattery, but ideally the imitation happens after we’ve had time to descend slowly from the peak – not the moment we plant the flag," say Asher Vollmer and Greg Wohlwend, the developers of the game. "Even writing this feels like we’re whining about some sour grapes that we have no business feeling sour about. Like it’s not OK to feel the way we do some of the time. But we do."

The trail from Threes, released onto the iOS App Store on 23 January, to 2048 is mostly public. First, on 27 February, was an iOS game called 1024, which copies Threes' aesthetic and gameplay, but simplifies some of the more complex elements of the game, making it easier in the process. More importantly, it undercuts the original's £1.49 price tag by being free. Until late March, the game's description on the App Store even began with "no need to pay for Threes!" It was also the first Threes clone available on Android devices.

2048 is mostly a clone of 1024 (a fact still acknowledged on the former's github page, where the code behind it is stored), but it is also "based on" another earlier game, also called 2048. When he shared it on hacker news, the second 2048's developer, Gabriele Cirulli, said he made it "to add animations to the [first 2048], which was a bit hard to play without them."

He also said that he had never heard of Threes, describing his game as "probably the last of a long chain of clones".

Cirulli's 2048 is an open-source project, meaning that anyone can use the code behind it to build their own versions of 2048. Despite a warning, added after it achieved success, that "this site is the official version of 2048… all other apps or sites are derivatives or fakes, and should be used with caution", those other versions have had their own success – perhaps even more than Cirulli's.

An iPhone clone, which itself claims to be "inspired by" Cirulli's version, has been in the top 10 list since it was released in mid-March. Another clone replaced all the numbers with images of Doge (a meme that involves pictures of a baffled yet placid shiba inu). That was then also cloned into an iPhone version.

Viral media site Us vs Th3m made a 2048-maker, allowing anyone to quickly clone the game themselves, while several other developers merged the game with other archetypes to create "Flappy 2048", which combines the aesthetics of the block puzzler with the gameplay of Flappy Bird.

All of which is overshadowing the developers of Threes. While 2048 was created in just one weekend – as the LA Times declared in wonder – it could only happen because the game was building on work that had taken more than a year to put together.

Along with their heartfelt letter, the developers released a mountain of material showing the development process the game went through. "Been in a bunch of airports this past week. Seen people playing 2048 in all of them. This is frustrating," tweeted Vollmer the day after he published the emails. "I want to move forward. I want to move on… It's hard feeling like one misstep (not making the game free) led to us missing our chance to be part of global culture."

Leigh Alexander, editor-at-large of gaming industry site Gamasutra, drily describes what's happening to Threes as "a unique tragedy". But Alexander also cautions against making Cirulli a villain figure.

"I thought, why don't I find this guy," she wrote. "Then I Googled and I realized Cirulli is just 19 years old, a web developer, one of countless digital tinkers who experiment with content often and in public… Young and thoughtless.

"This is going to happen, and this is going to keep happening."

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