By any measure, Threes is a success. The mobile puzzle game has been downloaded more than a million times, and even spawned a console version on Xbox One. But despite the sales and accolades, the developers behind it feel that it hasn’t really met its full potential. A lot of that has to do with the $2.99 price tag, and the strange debacle it unintentionally inspired. So today they’re making Threes free.

"Keeping such an accessible game behind a paywall has always felt like a misstep," says Threes designer Asher Vollmer.

The free version of the game has been in the works for around a year, and in that time the creators have been figuring out how to make the game free without ruining its appeal. There are no in-app purchases in the new version, or pop-up ads of any kind. Instead, in order to play you can earn credits by watching ads, and then spend them on rounds of Threes, sort of like an arcade machine. If the ads bug you, you can just pay the normal price to get rid of them.

One of the key sticking points, says Vollmer, was figuring out a way to make the game free, without inviting players to game the system and figure out ways to get more for nothing. "When I play a traditional free-to-play game, my instinct is ‘how much of this game can I play without spending a cent?’ and I know I'm not the only one who thinks this way," he explains. "This mentality is super toxic on both ends: the average player wants to avoid supporting the developer and the developer learns to rely solely on whales," a reference to the small percentage of players who make up the vast majority of purchases in free games.

One of the reasons Vollmer and artist Greg Wohlwend know that a free version of Threes could be successful is because it’s already happened. After Threes was released, the game was cloned many times, and copycat games like 2048 managed to reach a much larger audience largely because they were free. "2048 has mostly served as a constant, overwhelming reminder of our mistake," says Vollmer. "It taught us about the massive size of our potential audience." Wohlwend adds that "Threes is the original, the best, and the game that will stick. We're confident of that now and waiting to find the right solution for how to bring Threes to a wider audience is a result of that confidence."

Several games have similarly attempted to use a less exploitative form of monetization, though few have managed to see much success from it. Punch Quest infamously switched to a paid release after the free version proved to be a financial failure. But Vollmer believes the ad system they’ve created for Threes should help get around some of the typical pitfalls these games face. "I feel like the games that have tried — and failed — to do ethical free-to-play games in the past have all made a pretty critical mistake: they gave too much away for free," he explains. "Our model doesn't let you play very long without directly supporting us. You have to watch an ad to keep playing." The system was inspired by, of all things, Flappy Bird. "Flappy Bird was a nice and simple ad-supported game," says Wohlwend. "It felt honest and I think that's part of its success."

Since the initial release of Threes last February, both Vollmer and Wohlwend have continued to work on the game and its many ports, while also moving on to new projects. Wohlwend partnered with designer Mike Boxleiter to create the surveillance-themed puzzle game Touchtone this past March. Vollmer, meanwhile, has struggled to come up with a new game following the success of Threes, but recently released a fun new experiment with the peasant simulator Royals. In addition to the new version of the game, today the pair are also announcing the release of some beautiful new Threes art prints that fans can buy.

The hope is that the free release of Threes will not only help introduce the game to a new audience, but also help pay for the game’s continued existence; in addition to Wohlwend and Vollmer, Hidden Variable Studios is also still working on the game, primarily handling the Android version. But there’s also the fear that the free version will be so good that people will stop paying for Threes altogether.

"There's a chance that the free version will totally cannibalize our revenue and we will start earning zero dollars a day," says Vollmer. "I will consider this launch a success if that does not happen."

The free version of Threes is available to download today on iOS and Android.