In bringing Fortnite to Android this summer, Epic gambled that the biggest video game phenomenon in the world could find success without relying on the centralized Google Play storefront (and its 30 percent cut of all revenues). That gamble seems to have paid off so far—Epic reports 15 million Fortnite downloads and 23 million players on Android just 21 days after the game's beta release.

For context, the iOS version of the game saw roughly 11 million installations in its first month, according to analysis firm Sensor Tower, though the first two weeks of that period were a more limited "closed beta." It took the iOS version of Fortnite about three months to reach 100 million downloads, according to analysis firm Apptopia.

Technical hurdles

The Android launch numbers come directly from Epic, which goes on to detail the technical challenges of the Android port in a lengthy blog post.

Epic has so far limited the Fortnite Android beta to a small set of handsets released in the last two years, a fact that means 92 percent of Android Fortnite players are running Android 8 or newer. Despite working with the up-to-date software, the Fortnite team ran into a lot of headaches managing Android's fragmented hardware universe.

Memory management was chief among these problems: Epic found that even freshly restarted phones only allowed 50 to 75 percent of their total memory to be allocated by the game. Apps running in the background could cause persistent memory headaches, too, especially since some of those apps would automatically restart after Android tried to reclaim their memory footprints.

Such memory issues on 4GB phones were behind the laggy, stuttering performance we initially saw in our tests on the Galaxy S8+, Epic previously said.

Epic says it also ran into bugs in the early Vulkan API drivers supported by some recent Android phones, making OpenGL faster than Vulkan on most devices (though Vulkan ran 20 percent faster on the Samsung S9+ and Note 9). "The industry have had a decade to optimize and harden their implementations of OpenGL," Epic noted. "Vulkan is a more complex API and will take some time to reach the same level of maturity."

The blog post notably addresses the spate of malware developers that have tried to direct users to download fake Fortnite installers onto their devices. "So far, Epic has instigated action on 47 unauthorized 'Fortnite for Android' websites, many of which appear to be run by the same bad actors," the company said. Epic says it's working with browser makers and a third-party anti-fraud detection site to find and fight these sites as they pop up.