How one developer is sneaking emulators through a hole in the Xbox Store

Modern gaming consoles have exploded with indie games and apps, but one category has always proven an exception: emulators. This week, however, Ars has learned of an apparent loophole in Microsoft’s Xbox Store system being used to distribute high-performing emulators on the platform.

Microsoft usually doesn’t allow emulators to be published on the Xbox Store, though individual emulators have occasionally (and briefly) sneaked past Microsoft’s approval net in the past. Yesterday, we also wrote about how Xbox owners can use the system’s built-in Developer Mode as a workaround to install their own copy of the RetroArch emulator suite onto an Xbox Series X/S (or Xbox One).

But this new effort, led by a third-party app developer going by the handle tunip3, exploits an apparent hole in the Xbox app distribution system to let users download a “retail” version of RetroArch directly to the console’s main interface, without using Developer Mode.

That method involves publishing a slight modification of the existing UWP version of RetroArch as a “private” app, which doesn’t need to be reviewed by Microsoft, tunip3 says. That version can then be downloaded directly (using a code) by anyone whose email is placed on a whitelist. Tunip3 will be accepting applications for that whitelist through Friday, according to a message posted on Discord. (Ars will not be posting links to the Discord or whitelist application page.)

After installing RetroArch, Xbox users can download core updates through the suite’s own interface or access their own files through an app like My Files Explorer.

But why?

To distribute a “retail” version of RetroArch to Xbox consoles in the first place, Tunip3 tells Ars that it took some work “just going through trial and error to figure out how the store’s system works.” Going through that effort, they say, gets around some problems inherent in the extant Developer Mode version of the emulator suite. That includes a limit on accessing individual files larger than 2GB, which makes some Wii and Gamecube titles unplayable in Developer Mode. The retail version also lets Xbox users access apps like Spotify or their Xbox Live parties while playing.

This isn’t the first time tunip3 has distributed RetroArch to Xbox users using the same method. Back in July, they used a little publicized giveaway system to get the app to about 200 people and “keep it on the store for as long as possible.” That version was available for about a month, tunip3 said, before Microsoft discovered it and took it down. After that, users couldn’t redownload the app or any subsequent RetroArch updates, though previous downloads were left intact on users’ systems.

Now, however, tunip3 tells Ars, “we tried getting as many people on it as fast as possible at the risk of it potentially being found by Microsoft sooner. We have already got over 1,500 people on it this time [around].”

While tunip3 thinks Microsoft will eventually shut down this version of the app as well, he says he’s not too worried about potential repercussions. “I think they may ban my dev account, but I don’t think that I have harmed them or threatened them in any real way,” he said. “I doubt there will be any repercussions against the users, as there have been sketchier hidden apps in the past and when they were removed there were no repercussions imposed on the users.”

[Update: Following publication, tunip3 reached out to clarify that they are “not trying to break any rules or to damage Microsoft in any way,” that they are “not making any profit from the app, and if Microsoft had any questions or requests of me I would be happy to work with them if they reach out to me.”]

“[Microsoft] warns that it could ban developer accounts that consistently break the rules,” notes xBartenderx, an outside developer familiar with the effort who spoke to Ars over Discord. “What we don’t know is how tolerable they are with this.”

Microsoft has yet to respond to a request for comment from Ars Technica.